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authorTomas Winkler <tomas.winkler@intel.com>2019-12-12 10:41:03 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-10 13:20:49 +0100
commit1e8d19d9b0dfcf11b61bac627203a290577e807a (patch)
tree123cf1f4cd9e16334e4ce12c93f5965752911d83 /drivers/misc/mei/hdcp
parent49ef431defcc03be0d9bf80e1b3945a1c914868c (diff)
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: <stable@vger.kernel.org> v5.0+ Cc: Ramalingam C <ramalingam.c@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Reviewed-by: Alexander Usyskin <alexander.usyskin@intel.com> Link: https://lore.kernel.org/r/20191212084103.2893-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mei/hdcp')
-rw-r--r--drivers/misc/mei/hdcp/mei_hdcp.c33
1 files changed, 30 insertions, 3 deletions
diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index 93027fd96c71..4c596c646ac0 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -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;