From: Hermes Wu <hermes...@ite.com.tw> [ 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...@ite.com.tw> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delre...@collabora.com> Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-8-e0fdd4844...@ite.corp-partner.google.com Signed-off-by: Sasha Levin <sas...@kernel.org> --- drivers/gpu/drm/bridge/ite-it6505.c | 32 +++++++++++++++++------------ 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index 886e26a0000b4..1daa069d71f73 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2023,7 +2023,7 @@ 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) { @@ -2032,22 +2032,28 @@ 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) -- 2.39.5
