Patch "drm/bridge: it6505: fix HDCP CTS KSV list wait timer" has been added to the 6.12-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/bridge: it6505: fix HDCP CTS KSV list wait timer

to the 6.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-bridge-it6505-fix-hdcp-cts-ksv-list-wait-timer.patch
and it can be found in the queue-6.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1aaa65c610187412b015463bf4ea3c8c9040c3f9
Author: Hermes Wu <hermes.wu@xxxxxxxxxx>
Date:   Mon Dec 30 18:51:27 2024 +0800

    drm/bridge: it6505: fix HDCP CTS KSV list wait timer
    
    [ Upstream commit 9f9eef9ec1a2b57d95a86fe81df758e8253a7766 ]
    
    HDCP must disabled encryption and restart authentication after
    waiting KSV for 5s.
    The original method uses a counter in a waitting loop that may
    wait much longer than it is supposed to.
    Use time_after() for KSV wait timeout.
    
    Signed-off-by: Hermes Wu <hermes.wu@xxxxxxxxxx>
    Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
    Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-9-e0fdd4844703@xxxxxxxxxxxxxxxxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 029755ee21e23..faee8e2e82a05 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2061,12 +2061,13 @@ static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
 	struct it6505 *it6505 = container_of(work, struct it6505,
 					     hdcp_wait_ksv_list);
 	struct device *dev = it6505->dev;
-	unsigned int timeout = 5000;
-	u8 bstatus = 0;
+	u8 bstatus;
 	bool ksv_list_check;
+	/* 1B-04 wait ksv list for 5s */
+	unsigned long timeout = jiffies +
+				msecs_to_jiffies(5000) + 1;
 
-	timeout /= 20;
-	while (timeout > 0) {
+	for (;;) {
 		if (!it6505_get_sink_hpd_status(it6505))
 			return;
 
@@ -2075,13 +2076,12 @@ static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
 		if (bstatus & DP_BSTATUS_READY)
 			break;
 
-		msleep(20);
-		timeout--;
-	}
+		if (time_after(jiffies, timeout)) {
+			DRM_DEV_DEBUG_DRIVER(dev, "KSV list wait timeout");
+			goto timeout;
+		}
 
-	if (timeout == 0) {
-		DRM_DEV_DEBUG_DRIVER(dev, "timeout and ksv list wait failed");
-		goto timeout;
+		msleep(20);
 	}
 
 	ksv_list_check = it6505_hdcp_part2_ksvlist_check(it6505);