[PATCH v5 09/10] drm/bridge: it6505: fix HDCP CTS KSV list wait timer

[Hermes Wu]

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

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...@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c 
b/drivers/gpu/drm/bridge/ite-it6505.c
index da0ac789b8a3..2bf177a55daf 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2095,12 +2095,13 @@ 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;
 
@@ -2109,13 +2110,12 @@ 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);
-- 
2.34.1