From: Lee Shawn C <shawn.c.lee@intel.com>
To: dri-devel@lists.freedesktop.org
Cc: Cooper Chiou <cooper.chiou@intel.com>,
Jani Nikula <jani.nikula@intel.com>,
Lee Shawn C <shawn.c.lee@intel.com>
Subject: [PATCH v2] drm/edid: Select DMT timing if EDID's display feature not support GTF
Date: Mon, 7 Oct 2019 21:51:27 +0800 [thread overview]
Message-ID: <20191007135127.9538-1-shawn.c.lee@intel.com> (raw)
In-Reply-To: <20190806113021.6586-1-shawn.c.lee@intel.com>
Refer to EDID 1.3 spec, display FEATURE (byte 18h) bit #0 said
"If this bit is set to 1, the display supports timings based on the
GTF standard using default GTF parameter values".
And EDID 1.4 spec shows "If bit 0 is set to 0, then the display
is noncontinuous frequency (multi-mode) and is only specified to accept
the video timing formats that are listed in BASE EDID and certain
EXTENSION Blocks.
When display feature did not support CVT or GFT2 and monitor's EDID version
greater than or equal to "1.2". DRM driver would select GTF as default
for standard timing calculation. It may generated some video timing
that can't display properly by external monitor.
For example. When driver retrieved "0xD1 0xFC" (FHD, 120Hz) and
"0xD1 0xE8" (FHD, 100Hz) from "Standard Timings". GTF formula
would generate video timing like below. It already over monitor's
spec to cause black screen issue.
"1920x1080" 120 368881 1920 2072 2288 2656 1080 1081 1084 1157 0x0 0x6
"1920x1080" 100 301992 1920 2072 2280 2640 1080 1081 1084 1144 0x0 0x6
v2: Just confirm GTF flag and omit the revision check.
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Adam Jackson <ajax@redhat.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
---
drivers/gpu/drm/drm_edid.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 5aee0ebc200e..26eb04820b52 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2193,7 +2193,8 @@ static int standard_timing_level(struct edid *edid)
return LEVEL_CVT;
if (drm_gtf2_hbreak(edid))
return LEVEL_GTF2;
- return LEVEL_GTF;
+ if (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF)
+ return LEVEL_GTF;
}
return LEVEL_DMT;
}
--
2.17.1
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2019-10-07 5:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-06 11:30 [PATCH] drm/edid: Select DMT timing if EDID's display feature not support GTF Lee Shawn C
2019-08-19 16:39 ` Ville Syrjälä
2019-10-07 13:51 ` Lee Shawn C [this message]
2019-10-09 12:40 ` [PATCH v2] " Ville Syrjälä
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=20191007135127.9538-1-shawn.c.lee@intel.com \
--to=shawn.c.lee@intel.com \
--cc=cooper.chiou@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=jani.nikula@intel.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).