From: Douglas Anderson <dianders@chromium.org>
To: Thierry Reding <thierry.reding@gmail.com>,
Sam Ravnborg <sam@ravnborg.org>
Cc: robdclark@chromium.org, Douglas Anderson <dianders@chromium.org>,
Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH] drm: panel: simple: Set enable delay for BOE NV110WTM-N61
Date: Mon, 22 Feb 2021 08:17:24 -0800 [thread overview]
Message-ID: <20210222081716.1.I1a45aece5d2ac6a2e73bbec50da2086e43e0862b@changeid> (raw)
Panel power sequence says timing T8 (time from link idle to turn on
the backlight) should be at least 50 ms. This is what the .enable
delay in simple-panel is for, so set it. NOTE: this overlaps with the
80 ms .prepare_to_enable delay on purpose. The data sheet says that
at least 80 ms needs to pass between HPD going high and turning on the
backlight and that at least 50 ms needs to pass between the link idle
and the backlight going on. Thus it works like this on the system in
front of me:
* In bridge chip pre_enable call drm_panel_prepare()
* drm_panel_prepare() -> panel_simple_prepare()
* Wait for HPD GPIO to go high.
* Start counting for 80 ms (store in prepared_time)
* In bridge chip enable, train link then call drm_panel_enable()
* drm_panel_enable() -> panel_simple_enable()
* panel_simple_enable() does hardcoded 50 ms delay then enforces 80 ms
from HPD going high (in case the bridge took less than 30 ms to
enable / link train).
* drm_panel_enable() -> backlight_enable().
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
drivers/gpu/drm/panel/panel-simple.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 9858079f9e14..9d36b74357ae 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -1445,6 +1445,7 @@ static const struct panel_desc boe_nv110wtm_n61 = {
.delay = {
.hpd_absent_delay = 200,
.prepare_to_enable = 80,
+ .enable = 50,
.unprepare = 500,
},
.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
--
2.30.0.617.g56c4b15f3c-goog
reply other threads:[~2021-02-22 16:19 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210222081716.1.I1a45aece5d2ac6a2e73bbec50da2086e43e0862b@changeid \
--to=dianders@chromium.org \
--cc=airlied@linux.ie \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robdclark@chromium.org \
--cc=sam@ravnborg.org \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).