From: Hermes Wu hermes.wu@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.wu@ite.com.tw Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-8-e0fd... Signed-off-by: Sasha Levin sashal@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 9ef0ce2c2d14a..a563b81f7db8f 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2011,7 +2011,7 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505) { struct device *dev = &it6505->client->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) { @@ -2020,22 +2020,28 @@ 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)