6.1-stable review patch. If anyone has any objections, please let me know.
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From: Hermes Wu Hermes.wu@ite.com.tw
[ Upstream commit a5072fc77fb9e38fa9fd883642c83c3720049159 ]
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 Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Robert Foss rfoss@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20250121-fix-hdcp-v-comp-v4-1-... Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7c3bd539655b8..cc2bf9c143733 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2030,12 +2030,13 @@ 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; } }