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Check MST topology change on resume

PATCH RESEND In review Juston Li 5 participants 16 messages Oct 24, 2018 – Jun 15, 2019

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Juston Li

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#0 lore raw

v2 cover Check MST topology change on resume

Updated and resending these patches from Lyude:
https://lkml.org/lkml/2016/5/19/361
https://lkml.org/lkml/2016/5/19/360

As Lyude explains in patch 1/2, we can't rely on MST hubs to handle hotplugs during suspend. This patchset will check if any EDID's changed upon resume and reset the MST connections if they did.

This resolves issues with monitors not being detected when hotplugging them during suspend.

Signed-off-by Juston Li <[email protected]>

Changes since v1:
- update functions that have been renamed since the original patch
- add a null check for the cached EDID in case a new device was added
- checkpatch fixes

Lyude (2):
drm/dp/mst: Reprobe EDID for MST ports on resume drm/i915/mst: Reset MST after resume when necessary

 drivers/gpu/drm/drm_dp_mst_topology.c | 94 ++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_dp.c       |  7 +-
 2 files changed, 99 insertions(+), 2 deletions(-)
Signature · 6 lines
2.17.2

_______________________________________________
Intel-gfx mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
author
#1 lore raw

PATCH RESEND v2 1/2 drm/dp/mst: Reprobe EDID for MST ports on resume

From: Lyude <[email protected]>

As observed with the latest ThinkPad docks, we unfortunately can't rely on docks keeping us updated with hotplug events that happened while we were suspended. On top of that, even if the number of connectors remains the same between suspend and resume it's still not safe to assume that there were no hotplugs, since a different monitor might have been plugged into a port another monitor previously occupied. As such, we need to go through all of the MST ports and check whether or not their EDIDs have changed.

In addition to that, we also now return -EINVAL from drm_dp_mst_topology_mgr_resume to indicate to callers that they need to reset the MST connection, and that they can't rely on any other method of reprobing.

Cc [email protected]
Signed-off-by Lyude <[email protected]>
Signed-off-by Juston Li <[email protected]>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 94 ++++++++++++++++++++++++++-
 1 file changed, 93 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_dp_mst_topology.c +93 -1
index 5ff1d79b86c4..88abebe52021 100644
@@ -29,6 +29,7 @@
 #include <linux/i2c.h>
 #include <drm/drm_dp_mst_helper.h>
 #include <drm/drmP.h>
+#include <drm/drm_edid.h>
 
 #include <drm/drm_fixed.h>
 #include <drm/drm_atomic.h>

@@ -2201,6 +2202,64 @@ void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
 
+static bool drm_dp_mst_edids_changed(struct drm_dp_mst_topology_mgr *mgr,
+				     struct drm_dp_mst_port *port)
+{
+	struct drm_device *dev;
+	struct drm_connector *connector;
+	struct drm_dp_mst_port *dport;
+	struct drm_dp_mst_branch *mstb;
+	struct edid *current_edid, *cached_edid;
+	bool ret = false;
+
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return false;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
+	if (mstb) {
+		list_for_each_entry(dport, &port->mstb->ports, next) {
+			ret = drm_dp_mst_edids_changed(mgr, dport);
+			if (ret)
+				break;
+		}
+
+		drm_dp_put_mst_branch_device(mstb);
+		if (ret)
+			goto out;
+	}
+
+	connector = port->connector;
+	if (!connector || !port->aux.ddc.algo)
+		goto out;
+
+	dev = connector->dev;
+	mutex_lock(&dev->mode_config.mutex);
+
+	current_edid = drm_get_edid(connector, &port->aux.ddc);
+	if (connector->edid_blob_ptr)
+		cached_edid = (void *)connector->edid_blob_ptr->data;
+	else
+		return false;
+
+	if ((current_edid && cached_edid && memcmp(current_edid, cached_edid,
+						   sizeof(struct edid)) != 0) ||
+	    (!current_edid && cached_edid) || (current_edid && !cached_edid)) {
+		ret = true;
+		DRM_DEBUG_KMS("EDID on %s changed, reprobing connectors\n",
+			      connector->name);
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	kfree(current_edid);
+
+out:
+	drm_dp_put_port(port);
+
+	return ret;
+}
+
 /**
  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
  * @mgr: manager to resume

@@ -2210,9 +2269,15 @@ EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
  *
  * if the device fails this returns -1, and the driver should do
  * a full MST reprobe, in case we were undocked.
+ *
+ * if the device can no longer be trusted, this returns -EINVAL
+ * and the driver should unconditionally disconnect and reconnect
+ * the dock.
  */
 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
 {
+	struct drm_dp_mst_branch *mstb;
+	struct drm_dp_mst_port *port;
 	int ret = 0;
 
 	mutex_lock(&mgr->lock);

@@ -2246,8 +2311,35 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
 		drm_dp_check_mstb_guid(mgr->mst_primary, guid);
 
 		ret = 0;
-	} else
+
+		/*
+		 * Some hubs also forget to notify us of hotplugs that happened
+		 * while we were in suspend, so we need to verify that the edid
+		 * hasn't changed for any of the connectors. If it has been,
+		 * we unfortunately can't rely on the dock updating us with
+		 * hotplug events, so indicate we need a full reconnect.
+		 */
+
+		/* MST's I2C helpers can't be used while holding this lock */
+		mutex_unlock(&mgr->lock);
+
+		mstb = drm_dp_get_validated_mstb_ref(mgr, mgr->mst_primary);
+		if (mstb) {
+			list_for_each_entry(port, &mstb->ports, next) {
+				if (drm_dp_mst_edids_changed(mgr, port)) {
+					ret = -EINVAL;
+					break;
+				}
+			}
+
+			drm_dp_put_mst_branch_device(mstb);
+		}
+	} else {
 		ret = -1;
+		mutex_unlock(&mgr->lock);
+	}
+
+	return ret;
 
 out_unlock:
 	mutex_unlock(&mgr->lock);
Signature · 6 lines
2.17.2

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dri-devel mailing list
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#2 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Thought this was going to be an easy review until I realized that there's multiple problems in nouveau this would cause issues with, even if we didn't pay attention to the -EINVAL that gets returned. The suspend/resume order in nouveau needs some fixing up to prevent this patch from causing timeouts, and then also there's a hidden surprise

[  972.294437] ============================================
[  972.295225] WARNING: possible recursive locking detected
[  972.296042] 4.19.0-rc8mst-reprobe+ #2 Not tainted
[  972.296842] --------------------------------------------
[  972.297614] zsh/6840 is trying to acquire lock:
[  972.298441] 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.299299] 
               but task is already holding lock:
[  972.300991] 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
status_store+0x34/0x180 [drm]
[  972.301875] 
               other info that might help us debug this:
[  972.303563]  Possible unsafe locking scenario:
[  972.305315]        CPU0
[  972.306182]        ----
[  972.307061]   lock(&dev->mode_config.mutex);
[  972.307943]   lock(&dev->mode_config.mutex);
[  972.308819] 
                *** DEADLOCK ***
[  972.311446]  May be due to missing lock nesting notation
[  972.313234] 6 locks held by zsh/6840:
[  972.314135]  #0: 0000000092b5ba9d (sb_writers#4){.+.+}, at:
vfs_write+0x13e/0x1a0
[  972.315049]  #1: 00000000e628e6e9 (&of->mutex){+.+.}, at:
kernfs_fop_write+0xbd/0x1a0
[  972.315980]  #2: 000000000fb65e6c (kn->count#240){.+.+}, at:
kernfs_fop_write+0xc5/0x1a0
[  972.316928]  #3: 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
status_store+0x34/0x180 [drm]
[  972.317892]  #4: 00000000344224c2 (crtc_ww_class_acquire){+.+.}, at:
drm_helper_probe_single_connector_modes+0x66/0x6c0 [drm_kms_helper]
[  972.318863]  #5: 00000000d65352e2 (crtc_ww_class_mutex){+.+.}, at:
drm_modeset_lock+0x44/0x110 [drm]
[  972.319860] 
               stack backtrace:
[  972.321800] CPU: 5 PID: 6840 Comm: zsh Kdump: loaded Not tainted 4.19.0-
rc8mst-reprobe+ #2
[  972.322772] Hardware name: LENOVO 20EQZ1J7US/20EQZ1J7US, BIOS N1EET80W
(1.53 ) 09/14/2018
[  972.323792] Call Trace:
[  972.324821]  dump_stack+0x85/0xc0
[  972.325832]  __lock_acquire.cold.59+0x158/0x227
[  972.326887]  ? retint_kernel+0x10/0x10
[  972.327918]  lock_acquire+0x9e/0x170
[  972.328948]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.329986]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.331066]  __mutex_lock+0x68/0x900
[  972.332094]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.333146]  ? __mutex_unlock_slowpath+0x4b/0x2b0
[  972.334221]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.335255]  drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.336318]  drm_dp_mst_topology_mgr_resume+0x104/0x190 [drm_kms_helper]
[  972.337397]  nv50_display_init+0x73/0xd0 [nouveau]
[  972.338483]  nouveau_display_init+0x8e/0xe0 [nouveau]
[  972.339547]  nouveau_display_resume+0x39/0x250 [nouveau]
[  972.340634]  ? pci_restore_standard_config+0x40/0x40
[  972.341762]  nouveau_do_resume+0x79/0x150 [nouveau]
[  972.342850]  nouveau_pmops_runtime_resume+0x88/0x150 [nouveau]
[  972.343915]  pci_pm_runtime_resume+0x78/0xb0
[  972.345004]  __rpm_callback+0x75/0x1b0
[  972.346084]  ? pci_restore_standard_config+0x40/0x40
[  972.347148]  rpm_callback+0x1f/0x70
[  972.348256]  ? pci_restore_standard_config+0x40/0x40
[  972.349351]  rpm_resume+0x5d4/0x810
[  972.350446]  ? drm_modeset_lock+0x44/0x110 [drm]
[  972.351573]  __pm_runtime_resume+0x47/0x70
[  972.352737]  nouveau_connector_detect+0x373/0x470 [nouveau]
[  972.353841]  ? _cond_resched+0x15/0x30
[  972.354945]  ? ww_mutex_lock+0x30/0x60
[  972.356044]  ? drm_modeset_lock+0x44/0x110 [drm]
[  972.357146]  drm_helper_probe_single_connector_modes+0xd9/0x6c0
[drm_kms_helper]
[  972.358274]  ? printk+0x58/0x6f
[  972.359400]  status_store+0xb2/0x180 [drm]
[  972.360519]  kernfs_fop_write+0xf0/0x1a0
[  972.361711]  __vfs_write+0x36/0x180
[  972.362842]  ? rcu_read_lock_sched_held+0x55/0x60
[  972.363974]  ? rcu_sync_lockdep_assert+0x2e/0x60
[  972.365103]  ? __sb_start_write+0x115/0x170
[  972.366241]  ? vfs_write+0x13e/0x1a0
[  972.367365]  vfs_write+0xa5/0x1a0
[  972.368486]  ksys_write+0x52/0xc0
[  972.369596]  do_syscall_64+0x60/0x1a0
[  972.370782]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  972.371890] RIP: 0033:0x7fc93e169ef4
[  972.373012] Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00
00 66 90 48 8d 05 f1 3a 2d 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d
00 f0 ff ff 77 54 c3 0f 1f 00 41 54 49 89 d4 55 48 89 f5 53
[  972.374214] RSP: 002b:00007ffcd7ad1918 EFLAGS: 00000246 ORIG_RAX:
0000000000000001
[  972.375421] RAX: ffffffffffffffda RBX: 0000000000000007 RCX:
00007fc93e169ef4
[  972.376628] RDX: 0000000000000007 RSI: 000055aefe5c30c0 RDI:
0000000000000001
[  972.377872] RBP: 000055aefe5c30c0 R08: 00007fc93e43a8c0 R09:
00007fc93f6cdb80
[  972.379082] R10: 000000000000000a R11: 0000000000000246 R12:
00007fc93e439760
[  972.380311] R13: 0000000000000007 R14: 00007fc93e434760 R15:

0000000000000007

I must not have noticed that back when I wrote these patches! Whoops.

Since there's going to be quite a number of changes I need to make to this I'm just going to make the changes myself! I'll make sure to Cc you with the respin

Quoted 160 lines · Juston Li

From: Lyude <[email protected]>

As observed with the latest ThinkPad docks, we unfortunately can't rely on docks keeping us updated with hotplug events that happened while we were suspended. On top of that, even if the number of connectors remains the same between suspend and resume it's still not safe to assume that there were no hotplugs, since a different monitor might have been plugged into a port another monitor previously occupied. As such, we need to go through all of the MST ports and check whether or not their EDIDs have changed.

In addition to that, we also now return -EINVAL from drm_dp_mst_topology_mgr_resume to indicate to callers that they need to reset the MST connection, and that they can't rely on any other method of reprobing.

Cc [email protected]
Signed-off-by Lyude <[email protected]>
Signed-off-by Juston Li <[email protected]>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 94 ++++++++++++++++++++++++++-
 1 file changed, 93 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_dp_mst_topology.c +43 -0
index 5ff1d79b86c4..88abebe52021 100644
@@ -29,6 +29,7 @@
 #include <linux/i2c.h>
 #include <drm/drm_dp_mst_helper.h>
 #include <drm/drmP.h>
+#include <drm/drm_edid.h>
 
 #include <drm/drm_fixed.h>
 #include <drm/drm_atomic.h>

@@ -2201,6 +2202,64 @@ void drm_dp_mst_topology_mgr_suspend(struct
 drm_dp_mst_topology_mgr *mgr)
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
 
+static bool drm_dp_mst_edids_changed(struct drm_dp_mst_topology_mgr *mgr,
+				     struct drm_dp_mst_port *port)
+{
+	struct drm_device *dev;
+	struct drm_connector *connector;
+	struct drm_dp_mst_port *dport;
+	struct drm_dp_mst_branch *mstb;
+	struct edid *current_edid, *cached_edid;
+	bool ret = false;
+
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return false;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
+	if (mstb) {
+		list_for_each_entry(dport, &port->mstb->ports, next) {
+			ret = drm_dp_mst_edids_changed(mgr, dport);
+			if (ret)
+				break;
+		}
+
+		drm_dp_put_mst_branch_device(mstb);
+		if (ret)
+			goto out;
+	}
+
+	connector = port->connector;
+	if (!connector || !port->aux.ddc.algo)
+		goto out;
+
+	dev = connector->dev;
+	mutex_lock(&dev->mode_config.mutex);
+
+	current_edid = drm_get_edid(connector, &port->aux.ddc);
+	if (connector->edid_blob_ptr)
+		cached_edid = (void *)connector->edid_blob_ptr->data;
+	else
+		return false;
+
+	if ((current_edid && cached_edid && memcmp(current_edid, cached_edid,
+						   sizeof(struct edid)) != 0)

||

drivers/gpu/drm/drm_dp_mst_topology.c +1 -0
+	    (!current_edid && cached_edid) || (current_edid && !cached_edid))

{

drivers/gpu/drm/drm_dp_mst_topology.c +24 -1
+		ret = true;
+		DRM_DEBUG_KMS("EDID on %s changed, reprobing connectors\n",
+			      connector->name);
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	kfree(current_edid);
+
+out:
+	drm_dp_put_port(port);
+
+	return ret;
+}
+
 /**
  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
  * @mgr: manager to resume

@@ -2210,9 +2269,15 @@ EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
  *
  * if the device fails this returns -1, and the driver should do
  * a full MST reprobe, in case we were undocked.
+ *
+ * if the device can no longer be trusted, this returns -EINVAL
+ * and the driver should unconditionally disconnect and reconnect
+ * the dock.
  */
 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
 {
+	struct drm_dp_mst_branch *mstb;
+	struct drm_dp_mst_port *port;
 	int ret = 0;
 
 	mutex_lock(&mgr->lock);

@@ -2246,8 +2311,35 @@ int drm_dp_mst_topology_mgr_resume(struct
 drm_dp_mst_topology_mgr *mgr)
 		drm_dp_check_mstb_guid(mgr->mst_primary, guid);
 
 		ret = 0;
-	} else
+
+		/*
+		 * Some hubs also forget to notify us of hotplugs that

happened

drivers/gpu/drm/drm_dp_mst_topology.c +1 -0
+		 * while we were in suspend, so we need to verify that the

edid

drivers/gpu/drm/drm_dp_mst_topology.c +24 -0
+		 * hasn't changed for any of the connectors. If it has been,
+		 * we unfortunately can't rely on the dock updating us with
+		 * hotplug events, so indicate we need a full reconnect.
+		 */
+
+		/* MST's I2C helpers can't be used while holding this lock */
+		mutex_unlock(&mgr->lock);
+
+		mstb = drm_dp_get_validated_mstb_ref(mgr, mgr->mst_primary);
+		if (mstb) {
+			list_for_each_entry(port, &mstb->ports, next) {
+				if (drm_dp_mst_edids_changed(mgr, port)) {
+					ret = -EINVAL;
+					break;
+				}
+			}
+
+			drm_dp_put_mst_branch_device(mstb);
+		}
+	} else {
 		ret = -1;
+		mutex_unlock(&mgr->lock);
+	}
+
+	return ret;
 
 out_unlock:
 	mutex_unlock(&mgr->lock);
Signature · 2 lines
Cheers,
	Lyude Paul
author
#3 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Quoted 5 lines · Lyude Paul

Since there's going to be quite a number of changes I need to make to this I'm
just going to make the changes myself! I'll make sure to Cc you with the
respin

Sounds good, thanks for picking it up!

Juston

#4 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Are you still looking into this at all? Even if it's not the right approach I'm still interested in seeing this get fixed as well/discussing what I said before

Quoted 11 lines · Juston
Quoted 5 lines · Lyude Paul

Since there's going to be quite a number of changes I need to make to this I'm
just going to make the changes myself! I'll make sure to Cc you with the
respin

Sounds good, thanks for picking it up!

Juston

Signature · 2 lines
Cheers,
	Lyude Paul
author
#5 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Sorry for the late reply, email got caught in a bad filter =/

I haven't been looking into it lately but we are still interested in getting this fixed so I can start looking into this again.

In your last email you mentioned a sysfs hotplug could be the way to go?

Thanks
Juston

Quoted 20 lines · Lyude Paul

Are you still looking into this at all? Even if it's not the right approach
I'm still interested in seeing this get fixed as well/discussing what I said
before

Quoted 13 lines · Juston
Quoted 7 lines · Lyude Paul

Since there's going to be quite a number of changes I need to make to
this I'm
just going to make the changes myself! I'll make sure to Cc you with
the
respin

Sounds good, thanks for picking it up!

Juston

#6 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Quoted 7 lines · Juston

Sorry for the late reply, email got caught in a bad filter =/

I haven't been looking into it lately but we are still interested in getting this fixed so I can start looking into this again.

In your last email you mentioned a sysfs hotplug could be the way to go?

I had thought so; but I did a little more investigation and it looks like I wasn't totally wrong when I first wrote this patch; we actually do need to destroy the previous topology when it's not actually there and prevent the driver from trying to set it up again. Something that apparently a simple sysfs hotplug won't do.

I think what we might be able to do is instead of comparing against the connector's EDID, we should try repurposing drm_dp_mst_port->cached_edid so that it holds a copy of each mst connector's EDID instead of just logical MSTBs, then compare against those EDIDs instead of the ones we assigned to the drm_connector to avoid the lockdep issues that would occur from trying to grab dev->mode_config.mutex from the suspend/resume codepaths, and decide from where whether or not to tell the driver to cut off the topology.

Feel free to poke me about this on irc btw, might be quicker to discuss it there

Quoted 25 lines

Thanks
Juston

Quoted 20 lines · Lyude Paul

Are you still looking into this at all? Even if it's not the right approach
I'm still interested in seeing this get fixed as well/discussing what I said
before

Quoted 13 lines · Juston
Quoted 7 lines · Lyude Paul

Since there's going to be quite a number of changes I need to make to
this I'm
just going to make the changes myself! I'll make sure to Cc you with
the
respin

Sounds good, thanks for picking it up!

Juston

Signature · 2 lines
Cheers,
	Lyude Paul
#7 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

In reply to Lyude Paul

Gah, the more I think about this the more I realize this was never the correct approach to begin with. I wrote this patch a long time ago when I wasn't nearly as experienced, so that's not terribly surprising.

So: the thing is this isn't actually a problem that's specific to MST. Pretty much all of the different connector types have this issue, since any GPU is going to miss hotplugs if the entire system is in S3. So it doesn't make much sense to have this be in MST helpers; we should just reprobe all of the connectors on the system.

Honestly: I think it might just be a better idea to just send a sysfs hotplug when we wake up from suspend/resume, so that userspace just rechecks all of the connectors anyway. Nouveau already does this, jfyi.

Quoted 282 lines · Lyude Paul

Thought this was going to be an easy review until I realized that there's multiple problems in nouveau this would cause issues with, even if we didn't pay attention to the -EINVAL that gets returned. The suspend/resume order in nouveau needs some fixing up to prevent this patch from causing timeouts, and
then also there's a hidden surprise

[  972.294437] ============================================
[  972.295225] WARNING: possible recursive locking detected
[  972.296042] 4.19.0-rc8mst-reprobe+ #2 Not tainted
[  972.296842] --------------------------------------------
[  972.297614] zsh/6840 is trying to acquire lock:
[  972.298441] 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.299299] 
               but task is already holding lock:
[  972.300991] 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
status_store+0x34/0x180 [drm]
[  972.301875] 
               other info that might help us debug this:
[  972.303563]  Possible unsafe locking scenario:
[  972.305315]        CPU0
[  972.306182]        ----
[  972.307061]   lock(&dev->mode_config.mutex);
[  972.307943]   lock(&dev->mode_config.mutex);
[  972.308819] 
                *** DEADLOCK ***
[  972.311446]  May be due to missing lock nesting notation
[  972.313234] 6 locks held by zsh/6840:
[  972.314135]  #0: 0000000092b5ba9d (sb_writers#4){.+.+}, at:
vfs_write+0x13e/0x1a0
[  972.315049]  #1: 00000000e628e6e9 (&of->mutex){+.+.}, at:
kernfs_fop_write+0xbd/0x1a0
[  972.315980]  #2: 000000000fb65e6c (kn->count#240){.+.+}, at:
kernfs_fop_write+0xc5/0x1a0
[  972.316928]  #3: 0000000072e521f7 (&dev->mode_config.mutex){+.+.}, at:
status_store+0x34/0x180 [drm]
[  972.317892]  #4: 00000000344224c2 (crtc_ww_class_acquire){+.+.}, at:
drm_helper_probe_single_connector_modes+0x66/0x6c0 [drm_kms_helper]
[  972.318863]  #5: 00000000d65352e2 (crtc_ww_class_mutex){+.+.}, at:
drm_modeset_lock+0x44/0x110 [drm]
[  972.319860] 
               stack backtrace:
[  972.321800] CPU: 5 PID: 6840 Comm: zsh Kdump: loaded Not tainted 4.19.0-
rc8mst-reprobe+ #2
[  972.322772] Hardware name: LENOVO 20EQZ1J7US/20EQZ1J7US, BIOS N1EET80W
(1.53 ) 09/14/2018
[  972.323792] Call Trace:
[  972.324821]  dump_stack+0x85/0xc0
[  972.325832]  __lock_acquire.cold.59+0x158/0x227
[  972.326887]  ? retint_kernel+0x10/0x10
[  972.327918]  lock_acquire+0x9e/0x170
[  972.328948]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.329986]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.331066]  __mutex_lock+0x68/0x900
[  972.332094]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.333146]  ? __mutex_unlock_slowpath+0x4b/0x2b0
[  972.334221]  ? drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.335255]  drm_dp_mst_edids_changed+0xc0/0x180 [drm_kms_helper]
[  972.336318]  drm_dp_mst_topology_mgr_resume+0x104/0x190 [drm_kms_helper]
[  972.337397]  nv50_display_init+0x73/0xd0 [nouveau]
[  972.338483]  nouveau_display_init+0x8e/0xe0 [nouveau]
[  972.339547]  nouveau_display_resume+0x39/0x250 [nouveau]
[  972.340634]  ? pci_restore_standard_config+0x40/0x40
[  972.341762]  nouveau_do_resume+0x79/0x150 [nouveau]
[  972.342850]  nouveau_pmops_runtime_resume+0x88/0x150 [nouveau]
[  972.343915]  pci_pm_runtime_resume+0x78/0xb0
[  972.345004]  __rpm_callback+0x75/0x1b0
[  972.346084]  ? pci_restore_standard_config+0x40/0x40
[  972.347148]  rpm_callback+0x1f/0x70
[  972.348256]  ? pci_restore_standard_config+0x40/0x40
[  972.349351]  rpm_resume+0x5d4/0x810
[  972.350446]  ? drm_modeset_lock+0x44/0x110 [drm]
[  972.351573]  __pm_runtime_resume+0x47/0x70
[  972.352737]  nouveau_connector_detect+0x373/0x470 [nouveau]
[  972.353841]  ? _cond_resched+0x15/0x30
[  972.354945]  ? ww_mutex_lock+0x30/0x60
[  972.356044]  ? drm_modeset_lock+0x44/0x110 [drm]
[  972.357146]  drm_helper_probe_single_connector_modes+0xd9/0x6c0
[drm_kms_helper]
[  972.358274]  ? printk+0x58/0x6f
[  972.359400]  status_store+0xb2/0x180 [drm]
[  972.360519]  kernfs_fop_write+0xf0/0x1a0
[  972.361711]  __vfs_write+0x36/0x180
[  972.362842]  ? rcu_read_lock_sched_held+0x55/0x60
[  972.363974]  ? rcu_sync_lockdep_assert+0x2e/0x60
[  972.365103]  ? __sb_start_write+0x115/0x170
[  972.366241]  ? vfs_write+0x13e/0x1a0
[  972.367365]  vfs_write+0xa5/0x1a0
[  972.368486]  ksys_write+0x52/0xc0
[  972.369596]  do_syscall_64+0x60/0x1a0
[  972.370782]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  972.371890] RIP: 0033:0x7fc93e169ef4
[  972.373012] Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00
00
00 66 90 48 8d 05 f1 3a 2d 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d
00 f0 ff ff 77 54 c3 0f 1f 00 41 54 49 89 d4 55 48 89 f5 53
[  972.374214] RSP: 002b:00007ffcd7ad1918 EFLAGS: 00000246 ORIG_RAX:
0000000000000001
[  972.375421] RAX: ffffffffffffffda RBX: 0000000000000007 RCX:
00007fc93e169ef4
[  972.376628] RDX: 0000000000000007 RSI: 000055aefe5c30c0 RDI:
0000000000000001
[  972.377872] RBP: 000055aefe5c30c0 R08: 00007fc93e43a8c0 R09:
00007fc93f6cdb80
[  972.379082] R10: 000000000000000a R11: 0000000000000246 R12:
00007fc93e439760
[  972.380311] R13: 0000000000000007 R14: 00007fc93e434760 R15:

0000000000000007

I must not have noticed that back when I wrote these patches! Whoops.

Since there's going to be quite a number of changes I need to make to this I'm
just going to make the changes myself! I'll make sure to Cc you with the respin

Quoted 161 lines · Juston Li

From: Lyude <[email protected]>

As observed with the latest ThinkPad docks, we unfortunately can't rely on docks keeping us updated with hotplug events that happened while we were suspended. On top of that, even if the number of connectors remains the same between suspend and resume it's still not safe to assume that there were no hotplugs, since a different monitor might have been plugged into a port another monitor previously occupied. As such, we need to go through all of the MST ports and check whether or not their EDIDs have changed.

In addition to that, we also now return -EINVAL from drm_dp_mst_topology_mgr_resume to indicate to callers that they need to reset the MST connection, and that they can't rely on any other method of reprobing.

Cc [email protected]
Signed-off-by Lyude <[email protected]>
Signed-off-by Juston Li <[email protected]>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 94 ++++++++++++++++++++++++++-
 1 file changed, 93 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_dp_mst_topology.c +43 -0
index 5ff1d79b86c4..88abebe52021 100644
@@ -29,6 +29,7 @@
 #include <linux/i2c.h>
 #include <drm/drm_dp_mst_helper.h>
 #include <drm/drmP.h>
+#include <drm/drm_edid.h>
 
 #include <drm/drm_fixed.h>
 #include <drm/drm_atomic.h>

@@ -2201,6 +2202,64 @@ void drm_dp_mst_topology_mgr_suspend(struct
 drm_dp_mst_topology_mgr *mgr)
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
 
+static bool drm_dp_mst_edids_changed(struct drm_dp_mst_topology_mgr *mgr,
+				     struct drm_dp_mst_port *port)
+{
+	struct drm_device *dev;
+	struct drm_connector *connector;
+	struct drm_dp_mst_port *dport;
+	struct drm_dp_mst_branch *mstb;
+	struct edid *current_edid, *cached_edid;
+	bool ret = false;
+
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return false;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
+	if (mstb) {
+		list_for_each_entry(dport, &port->mstb->ports, next) {
+			ret = drm_dp_mst_edids_changed(mgr, dport);
+			if (ret)
+				break;
+		}
+
+		drm_dp_put_mst_branch_device(mstb);
+		if (ret)
+			goto out;
+	}
+
+	connector = port->connector;
+	if (!connector || !port->aux.ddc.algo)
+		goto out;
+
+	dev = connector->dev;
+	mutex_lock(&dev->mode_config.mutex);
+
+	current_edid = drm_get_edid(connector, &port->aux.ddc);
+	if (connector->edid_blob_ptr)
+		cached_edid = (void *)connector->edid_blob_ptr->data;
+	else
+		return false;
+
+	if ((current_edid && cached_edid && memcmp(current_edid, cached_edid,
+						   sizeof(struct edid)) != 0)
Quoted 1 line
Quoted 1 line
drivers/gpu/drm/drm_dp_mst_topology.c +1 -0
+	    (!current_edid && cached_edid) || (current_edid && !cached_edid))

{

drivers/gpu/drm/drm_dp_mst_topology.c +24 -1
+		ret = true;
+		DRM_DEBUG_KMS("EDID on %s changed, reprobing connectors\n",
+			      connector->name);
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	kfree(current_edid);
+
+out:
+	drm_dp_put_port(port);
+
+	return ret;
+}
+
 /**
  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
  * @mgr: manager to resume

@@ -2210,9 +2269,15 @@ EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
  *
  * if the device fails this returns -1, and the driver should do
  * a full MST reprobe, in case we were undocked.
+ *
+ * if the device can no longer be trusted, this returns -EINVAL
+ * and the driver should unconditionally disconnect and reconnect
+ * the dock.
  */
 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
 {
+	struct drm_dp_mst_branch *mstb;
+	struct drm_dp_mst_port *port;
 	int ret = 0;
 
 	mutex_lock(&mgr->lock);

@@ -2246,8 +2311,35 @@ int drm_dp_mst_topology_mgr_resume(struct
 drm_dp_mst_topology_mgr *mgr)
 		drm_dp_check_mstb_guid(mgr->mst_primary, guid);
 
 		ret = 0;
-	} else
+
+		/*
+		 * Some hubs also forget to notify us of hotplugs that

happened

drivers/gpu/drm/drm_dp_mst_topology.c +1 -0
+		 * while we were in suspend, so we need to verify that the

edid

drivers/gpu/drm/drm_dp_mst_topology.c +24 -0
+		 * hasn't changed for any of the connectors. If it has been,
+		 * we unfortunately can't rely on the dock updating us with
+		 * hotplug events, so indicate we need a full reconnect.
+		 */
+
+		/* MST's I2C helpers can't be used while holding this lock */
+		mutex_unlock(&mgr->lock);
+
+		mstb = drm_dp_get_validated_mstb_ref(mgr, mgr->mst_primary);
+		if (mstb) {
+			list_for_each_entry(port, &mstb->ports, next) {
+				if (drm_dp_mst_edids_changed(mgr, port)) {
+					ret = -EINVAL;
+					break;
+				}
+			}
+
+			drm_dp_put_mst_branch_device(mstb);
+		}
+	} else {
 		ret = -1;
+		mutex_unlock(&mgr->lock);
+	}
+
+	return ret;
 
 out_unlock:
 	mutex_unlock(&mgr->lock);
Signature · 7 lines
Cheers,
	Lyude Paul

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel
maintainer
#8 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

In reply to Juston Li

Hi,

[This is an automated email]

This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all

The bot has tested the following trees: v5.1.9, v4.19.50, v4.14.125, v4.9.181, v4.4.181.

v5.1.9: Build failed! Errors:
drivers/gpu/drm/drm_dp_mst_topology.c:2672:9: error: implicit declaration of function ‘drm_dp_get_validated_port_ref’; did you mean ‘drm_mode_validate_driver’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2676:9: error: implicit declaration of function ‘drm_dp_get_validated_mstb_ref’; did you mean ‘drm_mode_validate_size’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2684:3: error: implicit declaration of function ‘drm_dp_put_mst_branch_device’; did you mean ‘drm_dp_get_mst_branch_device’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2715:2: error: implicit declaration of function ‘drm_dp_put_port’; did you mean ‘drm_dp_get_port’? [-Werror=implicit-function-declaration]

v4.19.50: Build OK!
v4.14.125: Build OK!
v4.9.181: Build OK!
v4.4.181: Build OK!

How should we proceed with this patch?

--
Thanks,
Sasha

_______________________________________________
dri-devel mailing list
[email protected]
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#9 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

uh, Sasha not sure if you're a bot or not but this patch isn't even upstream

Quoted 34 lines · Sasha Levin

Hi,

[This is an automated email]

This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all

The bot has tested the following trees: v5.1.9, v4.19.50, v4.14.125, v4.9.181, v4.4.181.

v5.1.9: Build failed! Errors:

    drivers/gpu/drm/drm_dp_mst_topology.c:2672:9: error: implicit
declaration of function ‘drm_dp_get_validated_port_ref’; did you mean
‘drm_mode_validate_driver’? [-Werror=implicit-function-declaration]
    drivers/gpu/drm/drm_dp_mst_topology.c:2676:9: error: implicit
declaration of function ‘drm_dp_get_validated_mstb_ref’; did you mean
‘drm_mode_validate_size’? [-Werror=implicit-function-declaration]
    drivers/gpu/drm/drm_dp_mst_topology.c:2684:3: error: implicit
declaration of function ‘drm_dp_put_mst_branch_device’; did you mean
‘drm_dp_get_mst_branch_device’? [-Werror=implicit-function-declaration]
    drivers/gpu/drm/drm_dp_mst_topology.c:2715:2: error: implicit

declaration of function ‘drm_dp_put_port’; did you mean ‘drm_dp_get_port’? [-Werror=implicit-function-declaration]

v4.19.50: Build OK!
v4.14.125: Build OK!
v4.9.181: Build OK!
v4.4.181: Build OK!

How should we proceed with this patch?

--
Thanks,
Sasha

Signature · 2 lines
Cheers,
	Lyude Paul
maintainer
#10 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

Quoted 1 line · Lyude Paul

uh, Sasha not sure if you're a bot or not but this patch isn't even upstream

This is indeed a bot, and that's indeed it's purpose :)

We tend to get less responses if we wait for weeks for a patch to get upstream and queued for -stable because most often folks have moved on and forgotten all about it.

This bot looks for commits tagged for stable, and runs basic sanity checks on them while they're still being discussed on the mailing list. This way we get more responses with instructions on how to deal with the patch.

Either way, it won't be actually queued for stable before it's upstream.

maintainer
#11 lore raw

Re: [RESEND PATCH v2 1/2] drm/dp/mst: Reprobe EDID for MST ports on resume

In reply to Juston Li

Hi,

[This is an automated email]

This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all

The bot has tested the following trees: v5.1.9, v4.19.50, v4.14.125, v4.9.181, v4.4.181.

v5.1.9: Build failed! Errors:
drivers/gpu/drm/drm_dp_mst_topology.c:2672:9: error: implicit declaration of function ‘drm_dp_get_validated_port_ref’; did you mean ‘drm_mode_validate_driver’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2676:9: error: implicit declaration of function ‘drm_dp_get_validated_mstb_ref’; did you mean ‘drm_mode_validate_size’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2684:3: error: implicit declaration of function ‘drm_dp_put_mst_branch_device’; did you mean ‘drm_dp_get_mst_branch_device’? [-Werror=implicit-function-declaration] drivers/gpu/drm/drm_dp_mst_topology.c:2715:2: error: implicit declaration of function ‘drm_dp_put_port’; did you mean ‘drm_dp_get_port’? [-Werror=implicit-function-declaration]

v4.19.50: Build OK!
v4.14.125: Build OK!
v4.9.181: Build OK!
v4.4.181: Build OK!

How should we proceed with this patch?

--
Thanks,
Sasha

_______________________________________________
Intel-gfx mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

author
#12 lore raw

PATCH RESEND v2 2/2 drm/i915/mst: Reset MST after resume when necessary

In reply to Juston Li

From: Lyude <[email protected]>

A follow-up to the previous commit, we skip checking the status of the MST device and completely reprobe it if drm_dp_mst_topology_mgr_resume() returns -EINVAL.

Cc [email protected]
Signed-off-by Lyude <[email protected]>
Signed-off-by Juston Li <[email protected]>
---
 drivers/gpu/drm/i915/intel_dp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
drivers/gpu/drm/i915/intel_dp.c +6 -1
index 8c38efef77a1..cb5ffec73094 100644
@@ -6793,7 +6793,12 @@ void intel_dp_mst_resume(struct drm_i915_private *dev_priv)
 			continue;
 
 		ret = drm_dp_mst_topology_mgr_resume(&intel_dp->mst_mgr);
-		if (ret)
+		/* A full reset is required */
+		if (ret == -EINVAL) {
+			drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, false);
+			intel_dp_configure_mst(intel_dp);
+		} else if (ret != 0) {
 			intel_dp_check_mst_status(intel_dp);
+		}
 	}
 }
Signature · 6 lines
2.17.2

_______________________________________________
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https://lists.freedesktop.org/mailman/listinfo/intel-gfx
CI
#13 lore raw

✗ Fi.CI.BAT: failure for Check MST topology change on resume

In reply to Juston Li
== Series Details ==

== Series Details ==

Series: Check MST topology change on resume
URL : https://patchwork.freedesktop.org/series/51418/
State : failure

== Summary ==

= CI Bug Log - changes from CI_DRM_5023 -> Patchwork_10556 =

== Summary - FAILURE ==

Serious unknown changes coming with Patchwork_10556 absolutely need to be verified manually.

If you think the reported changes have nothing to do with the changes introduced in Patchwork_10556, please notify your bug team to allow them to document this new failure mode, which will reduce false positives in CI.

External URL: https://patchwork.freedesktop.org/api/1.0/series/51418/revisions/1/mbox/

== Possible new issues ==

Here are the unknown changes that may have been introduced in Patchwork_10556:

=== IGT changes ===

    ==== Possible regressions ====

    igt@gem_exec_nop@basic-series:
      fi-icl-u:           NOTRUN -> INCOMPLETE +1

    igt@pm_rps@basic-api:
      fi-kbl-7560u:       NOTRUN -> INCOMPLETE

== Known issues ==

Here are the changes found in Patchwork_10556 that come from known issues:

=== IGT changes ===

    ==== Issues hit ====

    igt@amdgpu/amd_basic@cs-compute:
      fi-kbl-8809g:       NOTRUN -> FAIL (fdo#108094)

    igt@amdgpu/amd_prime@amd-to-i915:
      fi-kbl-8809g:       NOTRUN -> FAIL (fdo#107341)

    igt@gem_exec_suspend@basic-s4-devices:
      fi-blb-e6850:       NOTRUN -> INCOMPLETE (fdo#107718)

    igt@kms_pipe_crc_basic@read-crc-pipe-b:
      fi-byt-clapper:     PASS -> FAIL (fdo#107362)

    
    ==== Possible fixes ====

    igt@drv_selftest@live_execlists:
      fi-apl-guc:         INCOMPLETE (fdo#106693) -> PASS

    igt@gem_ctx_switch@basic-default:
      fi-icl-u:           DMESG-FAIL -> PASS

    igt@gem_exec_suspend@basic-s3:
      fi-blb-e6850:       INCOMPLETE (fdo#107718) -> PASS

    igt@kms_pipe_crc_basic@read-crc-pipe-a:
      fi-byt-clapper:     FAIL (fdo#107362) -> PASS

fdo#106693 https://bugs.freedesktop.org/show_bug.cgi?id=106693
fdo#107341 https://bugs.freedesktop.org/show_bug.cgi?id=107341
fdo#107362 https://bugs.freedesktop.org/show_bug.cgi?id=107362
fdo#107718 https://bugs.freedesktop.org/show_bug.cgi?id=107718
fdo#108094 https://bugs.freedesktop.org/show_bug.cgi?id=108094

== Participating hosts (49 -> 45) ==

Additional (1): fi-kbl-7560u
Missing (5): fi-ilk-m540 fi-hsw-4200u fi-byt-squawks fi-bsw-cyan fi-ctg-p8600

== Build changes ==

* Linux: CI_DRM_5023 -> Patchwork_10556

CI_DRM_5023: 166bc98d7b77005943ab670506f164783cdc3f56 @ git://anongit.freedesktop.org/gfx-ci/linux
IGT_4688: fa6dbf8c048961356fd642df047cb58ab49309b2 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
Patchwork_10556: c8760e9a61bed1513da9a242ee70c29f9aa51aad @ git://anongit.freedesktop.org/gfx-ci/linux

== Linux commits ==

c8760e9a61be drm/i915/mst: Reset MST after resume when necessary b78ab9141ee9 drm/dp/mst: Reprobe EDID for MST ports on resume

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_10556/issues.html
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#14 lore raw
In reply to Juston Li
Quoted 4 lines · Juston Li

Updated and resending these patches from Lyude:
https://lkml.org/lkml/2016/5/19/361
https://lkml.org/lkml/2016/5/19/360

Quoted 8 lines

As Lyude explains in patch 1/2, we can't rely on MST hubs to handle hotplugs during suspend. This patchset will check if any EDID's changed upon resume and reset the MST connections if they did.

This resolves issues with monitors not being detected when hotplugging them during suspend.

Signed-off-by Juston Li <[email protected]>

For formality, does this also imply a reviewed-by tag?

For merging propably best we wait for the backmerge and the push these in through drm-misc-next-fixes.

Well for drm-misc-next-fixes drm-misc maintainers need to roll the tree forward. Either way needs synchronization. Plus an ack from drm-intel maintainers.
-Daniel

Quoted 21 lines

Changes since v1:
- update functions that have been renamed since the original patch
- add a null check for the cached EDID in case a new device was added
- checkpatch fixes

Lyude (2):
drm/dp/mst: Reprobe EDID for MST ports on resume drm/i915/mst: Reset MST after resume when necessary

 drivers/gpu/drm/drm_dp_mst_topology.c | 94 ++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_dp.c       |  7 +-
 2 files changed, 99 insertions(+), 2 deletions(-)
Signature · 6 lines
2.17.2

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Signature · 7 lines
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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author
#15 lore raw
Quoted 5 lines · Daniel Vetter
Quoted 2 lines · Juston Li
Signed-off-by Juston Li <[email protected]>

For formality, does this also imply a reviewed-by tag?

I'm quite new to drm so I'll withhold a reviewed-by tag and ask that someone else take a look at it too.

Lyude, the original author, mentioned he should probably take a look again also since the patchset is a bit old.

Quoted 10 lines

For merging propably best we wait for the backmerge and the push these in
through drm-misc-next-fixes.

Well for drm-misc-next-fixes drm-misc maintainers need to roll the tree
forward. Either way needs synchronization. Plus an ack from drm-intel maintainers.
-Daniel

Will do

Thanks
Juston
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