From: Harry Pan <harry.pan@intel.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: airlied@linux.ie, intel-gfx@lists.freedesktop.org,
Harry Pan <harry.pan@intel.com>,
dri-devel@lists.freedesktop.org, daniel.vetter@intel.com,
gs0622@gmail.com
Subject: [PATCH] drm/i915: minor corner case fix to respect user's backlight setting
Date: Fri, 27 Jan 2017 20:57:40 +0800 [thread overview]
Message-ID: <1485521860-682-1-git-send-email-harry.pan@intel.com> (raw)
When enabling panel backlight, if the current backlight level
setting matches the panel's minimal, it would apply default policy to
override the current level by the panel's maximum until next request
to update brightness, this leads unexpected user confusion with
temporary full power backlight.
This odd could be reproduced as commands like these:
$ xbacklight -set 0
$ sudo sh -c 'echo mem > /sys/power/state'
(resume)
To fix this, slightly tinker the backlight level comparison from
'less-and-equal-to' to 'less-than'.
Before: (dmesg | grep backlight # with drm.debug=0xe)
[ 82.249265] [drm:intel_backlight_device_update_status [i915]] updating intel_backlight, brightness=0/5273
[ 82.249282] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207
[ 82.249306] [drm:intel_edp_backlight_power [i915]] panel power control backlight disable
[ 92.066041] [drm:intel_edp_backlight_off [i915]]
[ 92.270489] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 0
[ 94.080434] [drm:intel_edp_backlight_on.part.25 [i915]]
[ 94.080476] [drm:intel_panel_enable_backlight [i915]] pipe A
[ 94.080539] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 5273
After:
[ 72.874465] [drm:intel_backlight_device_update_status [i915]] updating intel_backlight, brightness=0/5273
[ 72.874499] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207
[ 72.874540] [drm:intel_edp_backlight_power [i915]] panel power control backlight disable
[ 86.807928] [drm:intel_edp_backlight_off [i915]]
[ 87.013227] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 0
[ 89.001829] [drm:intel_edp_backlight_on.part.25 [i915]]
[ 89.001859] [drm:intel_panel_enable_backlight [i915]] pipe A
[ 89.001926] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207
Fixes: 13f3fbe827d0 ("fix inconsistent brightness after resume")
Signed-off-by: Harry Pan <harry.pan@intel.com>
---
drivers/gpu/drm/i915/intel_panel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 08ab6d7..e882139 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -1104,7 +1104,7 @@ void intel_panel_enable_backlight(struct intel_connector *connector)
WARN_ON(panel->backlight.max == 0);
- if (panel->backlight.level <= panel->backlight.min) {
+ if (panel->backlight.level < panel->backlight.min) {
panel->backlight.level = panel->backlight.max;
if (panel->backlight.device)
panel->backlight.device->props.brightness =
--
2.6.6
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next reply other threads:[~2017-01-27 12:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-27 12:57 Harry Pan [this message]
2017-01-27 14:10 ` [PATCH] drm/i915: minor corner case fix to respect user's backlight setting Jani Nikula
2017-01-30 11:54 ` ✓ Fi.CI.BAT: success for " Patchwork
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=1485521860-682-1-git-send-email-harry.pan@intel.com \
--to=harry.pan@intel.com \
--cc=airlied@linux.ie \
--cc=daniel.vetter@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=gs0622@gmail.com \
--cc=intel-gfx@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
/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