| Message ID | 20250121-fix-hdcp-v-comp-v4-1-185f45c728dc@ite.com.tw (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v4] drm/bridge: it6505: fix HDCP V match check is not performed correctly | expand |
On Tue, Jan 21, 2025 at 03:01:51PM +0800, Hermes Wu via B4 Relay wrote: > From: Hermes Wu <Hermes.wu@ite.com.tw> > > 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@ite.com.tw> > --- > 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@ite.com.tw > > 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@ite.com.tw > > 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@ite.com.tw > --- > drivers/gpu/drm/bridge/ite-it6505.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
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; } }