Commit 0989c02c authored by Hermes Wu's avatar Hermes Wu Committed by Dmitry Baryshkov
Browse files

drm/bridge: it6505: fix HDCP CTS compare V matching 



When HDCP negotiation with a repeater device.
Checking SHA V' matching must retry 3 times before restarting HDCP.

Signed-off-by: default avatarHermes Wu <hermes.wu@ite.com.tw>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-8-e0fdd4844703@ite.corp-partner.google.com
parent aa972393

drivers/gpu/drm/bridge/ite-it6505.c

+19 −13
Original line number Diff line number Diff line
@@ -2058,7 +2058,7 @@ 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) {
@@ -2067,23 +2067,29 @@ 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));



		if (err < 0) {

		dev_err(dev, "Read V' value Fail");

		return false;

			dev_err(dev, "Read V' value Fail %d", retry);

			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] ||

		    bv[i][1] != av[i][2] || bv[i][0] != av[i][3])

			return false;

			    av[i][1] != av[i][2] || bv[i][0] != av[i][3])

				break;



	DRM_DEV_DEBUG_DRIVER(dev, "V' all match!!");

			DRM_DEV_DEBUG_DRIVER(dev, "V' all match!! %d, %d", retry, i);

			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)

{