lkml.org 
[lkml]   [2022]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 3/3] drm/msm/dp: retry 3 times if set sink to D0 poweer state failed
Date
Bring sink out of D3 (power down) mode into D0 (normal operation) mode
by setting DP_SET_POWER_D0 bit to DP_SET_POWER dpcd register. This
patch will retry 3 times if written to DP_SET_POWER register failed.

Changes in v5:
-- split into two patches

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
---
drivers/gpu/drm/msm/dp/dp_link.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index 9d5381d..4360728 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -50,6 +50,7 @@ static int dp_aux_link_power_up(struct drm_dp_aux *aux,
{
u8 value;
ssize_t len;
+ int i;

if (link->revision < 0x11)
return 0;
@@ -61,11 +62,13 @@ static int dp_aux_link_power_up(struct drm_dp_aux *aux,
value &= ~DP_SET_POWER_MASK;
value |= DP_SET_POWER_D0;

- len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
- if (len < 0)
- return len;
-
- usleep_range(1000, 2000);
+ /* retry for 1ms to give the sink time to wake up */
+ for (i = 0; i < 3; i++) {
+ len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
+ usleep_range(1000, 2000);
+ if (len == 1)
+ break;
+ }

return 0;
}
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
\
 
 \ /
  Last update: 2022-09-12 18:30    [W:0.057 / U:0.836 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site