Patch "Bluetooth: btusb: Use DMI matching for QCA reset_resume quirking" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

Bluetooth: btusb: Use DMI matching for QCA reset_resume quirking

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
bluetooth-btusb-use-dmi-matching-for-qca-reset_resume-quirking.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Hans de Goede <[email protected]>
Date: Tue, 20 Feb 2018 09:06:18 +0100
Subject: Bluetooth: btusb: Use DMI matching for QCA reset_resume quirking

From: Hans de Goede <[email protected]>

commit 1fdb926974695d3dbc05a429bafa266fdd16510e upstream.

Commit 61f5acea8737 ("Bluetooth: btusb: Restore QCA Rome suspend/resume fix with a "rewritten" version") applied the USB_QUIRK_RESET_RESUME to all QCA USB Bluetooth modules. But it turns out that the resume problems are not caused by the QCA Rome chipset, on most platforms it resumes fine. The resume problems are actually a platform problem (likely the platform cutting all power when suspended).

The USB_QUIRK_RESET_RESUME quirk also disables runtime suspend, so by matching on usb-ids, we're causing all boards with these chips to use extra power, to fix resume problems which only happen on some boards.

This commit fixes this by applying the quirk based on DMI matching instead of on usb-ids, so that we match the platform and not the chipset.

Here is the /sys/kernel/debug/usb/devices for the Bluetooth module:

T:  Bus=01 Lev=01 Prnt=01 Port=07 Cnt=04 Dev#=  5 Spd=12   MxCh= 0
D:  Ver= 2.01 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0cf3 ProdID=e300 Rev= 0.01
C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=1ms
E:  Ad=82(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   0 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   0 Ivl=1ms
I:  If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   9 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   9 Ivl=1ms
I:  If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  17 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  17 Ivl=1ms
I:  If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  25 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  25 Ivl=1ms
I:  If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  33 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  33 Ivl=1ms
I:  If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  49 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  49 Ivl=1ms

---
 drivers/bluetooth/btusb.c |   25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

@@ -21,6 +21,7 @@
  *
  */
 
+#include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include <linux/usb/quirks.h>

@@ -358,6 +359,21 @@ static const struct usb_device_id blackl
 	{ }	/* Terminating entry */
 };
 
+/* The Bluetooth USB module build into some devices needs to be reset on resume,
+ * this is a problem with the platform (likely shutting off all power) not with
+ * the module itself. So we use a DMI list to match known broken platforms.
+ */
+static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
+	{
+		/* Lenovo Yoga 920 (QCA Rome device 0cf3:e300) */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo YOGA 920"),
+		},
+	},
+	{}
+};
+
 #define BTUSB_MAX_ISOC_FRAMES	10
 
 #define BTUSB_INTR_RUNNING	0

@@ -2926,12 +2942,6 @@ static int btusb_probe(struct usb_interf
 	if (id->driver_info & BTUSB_QCA_ROME) {
 		data->setup_on_usb = btusb_setup_qca;
 		hdev->set_bdaddr = btusb_set_bdaddr_ath3012;
-
-		/* QCA Rome devices lose their updated firmware over suspend,
-		 * but the USB hub doesn't notice any status change.
-		 * explicitly request a device reset on resume.
-		 */
-		interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME;
 	}
 
 #ifdef CONFIG_BT_HCIBTUSB_RTL

@@ -3074,6 +3084,9 @@ static void btusb_disconnect(struct usb_
 	hci_free_dev(hdev);
 }
 
+	if (dmi_check_system(btusb_needs_reset_resume_table))
+		interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME;
+
 #ifdef CONFIG_PM
 static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
 {

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/bluetooth-btusb-use-dmi-matching-for-qca-reset_resume-quirking.patch