From: Hermes Wu Date: Tue, 21 Jan 2025 07:01:51 +0000 (+0800) Subject: drm/bridge: it6505: fix HDCP V match check is not performed correctly X-Git-Tag: v6.12.23~374 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dd8e6445e4e33e0f363d614bd02a7e6195660bcc;p=thirdparty%2Fkernel%2Fstable.git drm/bridge: it6505: fix HDCP V match check is not performed correctly [ 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 Reviewed-by: Dmitry Baryshkov Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20250121-fix-hdcp-v-comp-v4-1-185f45c728dc@ite.com.tw Signed-off-by: Sasha Levin --- diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index faee8e2e82a05..967aa24b7c537 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2042,12 +2042,13 @@ 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; } }