This is a note to let you know that I've just added the patch titled
drm/bridge: it6505: fix HDCP CTS compare V matching
to the 6.6-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:
drm-bridge-it6505-fix-hdcp-cts-compare-v-matching.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b2a802d7dcfd635ece232b9731461a33a40f6352
Author: Hermes Wu <hermes.wu@xxxxxxxxxx>
Date: Mon Dec 30 18:51:26 2024 +0800
drm/bridge: it6505: fix HDCP CTS compare V matching
[ Upstream commit 0989c02c7a5c887c70afeae80c64d0291624e1a7 ]
When HDCP negotiation with a repeater device.
Checking SHA V' matching must retry 3 times before restarting HDCP.
Signed-off-by: Hermes Wu <hermes.wu@xxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-8-e0fdd4844703@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index f9f67e172eeee..552d33c4325af 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2020,7 +2020,7 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505)
{
struct device *dev = it6505->dev;
u8 av[5][4], bv[5][4];
- int i, err;
+ int i, err, retry;
i = it6505_setup_sha1_input(it6505, it6505->sha1_input);
if (i <= 0) {
@@ -2029,22 +2029,28 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505)
}
it6505_sha1_digest(it6505, it6505->sha1_input, i, (u8 *)av);
+ /*1B-05 V' must retry 3 times */
+ for (retry = 0; retry < 3; retry++) {
+ err = it6505_get_dpcd(it6505, DP_AUX_HDCP_V_PRIME(0), (u8 *)bv,
+ sizeof(bv));
- err = it6505_get_dpcd(it6505, DP_AUX_HDCP_V_PRIME(0), (u8 *)bv,
- sizeof(bv));
+ if (err < 0) {
+ dev_err(dev, "Read V' value Fail %d", retry);
+ continue;
+ }
- if (err < 0) {
- dev_err(dev, "Read V' value Fail");
- return false;
- }
+ for (i = 0; i < 5; i++) {
+ if (bv[i][3] != av[i][0] || bv[i][2] != av[i][1] ||
+ av[i][1] != av[i][2] || bv[i][0] != av[i][3])
+ break;
- for (i = 0; i < 5; i++)
- if (bv[i][3] != av[i][0] || bv[i][2] != av[i][1] ||
- bv[i][1] != av[i][2] || bv[i][0] != av[i][3])
- return false;
+ DRM_DEV_DEBUG_DRIVER(dev, "V' all match!! %d, %d", retry, i);
+ return true;
+ }
+ }
- DRM_DEV_DEBUG_DRIVER(dev, "V' all match!!");
- return true;
+ DRM_DEV_DEBUG_DRIVER(dev, "V' NOT match!! %d", retry);
+ return false;
}
static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
