linux-kernel - [PATCH AUTOSEL 6.1 6/9] drm/bridge: it6505: fix HDCP Bstatus check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250126145651.943149-6-sashal@kernel.org>
Date: Sun, 26 Jan 2025 09:56:48 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Hermes Wu <hermes.wu@....com.tw>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Sasha Levin <sashal@...nel.org>,
	andrzej.hajda@...el.com,
	neil.armstrong@...aro.org,
	rfoss@...nel.org,
	maarten.lankhorst@...ux.intel.com,
	mripard@...nel.org,
	tzimmermann@...e.de,
	airlied@...il.com,
	simona@...ll.ch,
	dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.1 6/9] drm/bridge: it6505: fix HDCP Bstatus check

From: Hermes Wu <hermes.wu@....com.tw>

[ Upstream commit 0fd2ff47d8c207fa3173661de04bb9e8201c0ad2 ]

When HDCP is activated,
a DisplayPort source receiving CP_IRQ from the sink
shall check Bstatus from DPCD and process the corresponding value

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Signed-off-by: Hermes Wu <hermes.wu@....com.tw>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-5-e0fdd4844703@ite.corp-partner.google.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 3a15cd170fe4d..32c401ab72a60 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2292,14 +2292,20 @@ static int it6505_process_hpd_irq(struct it6505 *it6505)
 	DRM_DEV_DEBUG_DRIVER(dev, "dp_irq_vector = 0x%02x", dp_irq_vector);
 
 	if (dp_irq_vector & DP_CP_IRQ) {
-		it6505_set_bits(it6505, REG_HDCP_TRIGGER, HDCP_TRIGGER_CPIRQ,
-				HDCP_TRIGGER_CPIRQ);
-
 		bstatus = it6505_dpcd_read(it6505, DP_AUX_HDCP_BSTATUS);
 		if (bstatus < 0)
 			return bstatus;
 
 		DRM_DEV_DEBUG_DRIVER(dev, "Bstatus = 0x%02x", bstatus);
+
+		/*Check BSTATUS when recive CP_IRQ */
+		if (bstatus & DP_BSTATUS_R0_PRIME_READY &&
+		    it6505->hdcp_status == HDCP_AUTH_GOING)
+			it6505_set_bits(it6505, REG_HDCP_TRIGGER, HDCP_TRIGGER_CPIRQ,
+					HDCP_TRIGGER_CPIRQ);
+		else if (bstatus & (DP_BSTATUS_REAUTH_REQ | DP_BSTATUS_LINK_FAILURE) &&
+			 it6505->hdcp_status == HDCP_AUTH_DONE)
+			it6505_start_hdcp(it6505);
 	}
 
 	ret = drm_dp_dpcd_read_link_status(&it6505->aux, link_status);
-- 
2.39.5