patch "mei: hdcp: bind only with i915 on the same PCH" added to char-misc-testing

PATCH [email protected] 1 participant 1 message Jan 10, 2020

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Stable branch Char and misc drivers Intel management engine (mei)

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2020-01-10 12:24 UTC #0 lore raw

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

mei: hdcp: bind only with i915 on the same PCH

to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From 1e8d19d9b0dfcf11b61bac627203a290577e807a Mon Sep 17 00:00:00 2001
From: Tomas Winkler <[email protected]>
Date: Thu, 12 Dec 2019 10:41:03 +0200
Subject: mei: hdcp: bind only with i915 on the same PCH

The mei device and i915 must reside on the same
PCH in order for HDCP to work. Make the component
matching function enforce this requirement.

                   hdcp
                    |
   i915            mei
    |               |
    +----= PCH =----+

Cc <[email protected]> v5.0+

Cc Ramalingam C <[email protected]>

Signed-off-by Tomas Winkler <[email protected]>

Reviewed-by Alexander Usyskin <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/misc/mei/hdcp/mei_hdcp.c | 33 +++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

drivers/misc/mei/hdcp/mei_hdcp.c +30 -3

index 93027fd96c71..4c596c646ac0 100644
@@ -757,11 +757,38 @@ static const struct component_master_ops mei_component_master_ops = {
 	.unbind = mei_component_master_unbind,
 };
 
+/**
+ * mei_hdcp_component_match - compare function for matching mei hdcp.
+ *
+ *    The function checks if the driver is i915, the subcomponent is HDCP
+ *    and the grand parent of hdcp and the parent of i915 are the same
+ *    PCH device.
+ *
+ * @dev: master device
+ * @subcomponent: subcomponent to match (I915_COMPONENT_HDCP)
+ * @data: compare data (mei hdcp device)
+ *
+ * Return:
+ * * 1 - if components match
+ * * 0 - otherwise
+ */
 static int mei_hdcp_component_match(struct device *dev, int subcomponent,
 				    void *data)
 {
-	return !strcmp(dev->driver->name, "i915") &&
-	       subcomponent == I915_COMPONENT_HDCP;
+	struct device *base = data;
+
+	if (strcmp(dev->driver->name, "i915") ||
+	    subcomponent != I915_COMPONENT_HDCP)
+		return 0;
+
+	base = base->parent;
+	if (!base)
+		return 0;
+
+	base = base->parent;
+	dev = dev->parent;
+
+	return (base && dev && dev == base);
 }
 
 static int mei_hdcp_probe(struct mei_cl_device *cldev,

@@ -785,7 +812,7 @@ static int mei_hdcp_probe(struct mei_cl_device *cldev,
 
 	master_match = NULL;
 	component_match_add_typed(&cldev->dev, &master_match,
-				  mei_hdcp_component_match, comp_master);
+				  mei_hdcp_component_match, &cldev->dev);
 	if (IS_ERR_OR_NULL(master_match)) {
 		ret = -ENOMEM;
 		goto err_exit;

Signature · 1 line

2.24.1