From: Hermes Wu <Hermes.wu@xxxxxxxxxx>
Fix a typo where V compare incorrectly compares av[] with av[] itself,
which can result in HDCP failure.
The loop of V compare is expected to iterate for 5 times
which compare V array form av[0][] to av[4][].
It should check loop counter reach the last statement "i == 5"
before return true
Fixes: 0989c02c7a5c ("drm/bridge: it6505: fix HDCP CTS compare V matching")
Signed-off-by: Hermes Wu <Hermes.wu@xxxxxxxxxx>
---
Changes in v4:
- Fix a typo where V compare incorrectly compares av[] with av[] itself
- Link to v3: https://lore.kernel.org/r/20250109-fix-hdcp-v-comp-v3-1-1258edb249ab@xxxxxxxxxx
Changes in v3:
- The V value compare loop from i = 0 to i = 4 and shall exit with i == 5
if all V element matches
- Link to v2: https://lore.kernel.org/r/20250109-fix-hdcp-v-comp-v2-1-7dce0a59523f@xxxxxxxxxx
Changes in v2:
- pull the check of statment "i" out of V value check loop
- Link to v1: https://lore.kernel.org/r/20250108-fix-hdcp-v-comp-v1-1-9404811825cd@xxxxxxxxxx
---
drivers/gpu/drm/bridge/ite-it6505.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 88ef76a37fe6accacdd343839ff2569b31b18ceb..76dabca04d0d191b3bdee23c6a3e55f4b6d3bad4 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2250,12 +2250,13 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505)
continue;
}
- for (i = 0; i < 5; i++) {
+ 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])
+ bv[i][1] != av[i][2] || bv[i][0] != av[i][3])
break;
- DRM_DEV_DEBUG_DRIVER(dev, "V' all match!! %d, %d", retry, i);
+ if (i == 5) {
+ DRM_DEV_DEBUG_DRIVER(dev, "V' all match!! %d", retry);
return true;
}
}
---
base-commit: 938fbb16aba8f7b88e0fdcf56f315a5bbad41aad
change-id: 20250107-fix-hdcp-v-comp-3ba8e3d7adf3
Best regards,
--
Hermes Wu <Hermes.wu@xxxxxxxxxx>
