From 43b9e14772907b3166085bdab44e4383b6fdd5df Mon Sep 17 00:00:00 2001
From: yangcong <yangcong5@huaqin.corp-partner.google.com>
Date: Fri, 12 Nov 2021 16:43:02 +0800
Subject: drm/bridge: parade-ps8640: Fix additional suspend/resume at bootup
Git-commit: aa70a0996b0ee5950237cfe5f039285eda0c1470
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Through log and waveform, we can see that there will be additional
suspend/resume when booting. This timing does not meet the ps8640 spec.
It seems that the delay of 500ms does not satisfied drm_panel_get_modes.
I increased it to 900ms and it seems that this problem can be solved.
To be safe, I'd just round up to a full 1000.
Signed-off-by: yangcong <yangcong5@huaqin.corp-partner.google.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211112084302.2447931-1-yangcong5@huaqin.corp-partner.google.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/bridge/parade-ps8640.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 345bb2b4e15d..26898042ba3d 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -634,13 +634,13 @@ static int ps8640_probe(struct i2c_client *client)
pm_runtime_enable(dev);
/*
* Powering on ps8640 takes ~300ms. To avoid wasting time on power
- * cycling ps8640 too often, set autosuspend_delay to 500ms to ensure
+ * cycling ps8640 too often, set autosuspend_delay to 1000ms to ensure
* the bridge wouldn't suspend in between each _aux_transfer_msg() call
* during EDID read (~20ms in my experiment) and in between the last
* _aux_transfer_msg() call during EDID read and the _pre_enable() call
* (~100ms in my experiment).
*/
- pm_runtime_set_autosuspend_delay(dev, 500);
+ pm_runtime_set_autosuspend_delay(dev, 1000);
pm_runtime_use_autosuspend(dev);
pm_suspend_ignore_children(dev, true);
ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);
--
2.38.1