From: Daniel Vetter <daniel@ffwll.ch>
To: Adam Jackson <ajax@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm/edid: Make the detailed timing CEA/HDMI mode fixup accept up to 5kHz clock difference
Date: Tue, 1 Dec 2015 07:57:46 +0100 [thread overview]
Message-ID: <20151201065746.GB17050@phenom.ffwll.local> (raw)
In-Reply-To: <1448906579.4256.57.camel@redhat.com>
On Mon, Nov 30, 2015 at 01:02:59PM -0500, Adam Jackson wrote:
> On Thu, 2015-11-26 at 19:01 +0200, Ville Syrjälä wrote:
> > On Mon, Nov 16, 2015 at 09:05:12PM +0200, ville.syrjala@linux.intel.com wrote:
> > > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > >
> > > Rather than using drm_match_cea_mode() to see if the EDID detailed
> > > timings are supposed to represent one of the CEA/HDMI modes, add a
> > > special version of that function that takes in an explicit clock
> > > tolerance value (in kHz). When looking at the detailed timings specify
> > > the tolerance as 5kHz due to the 10kHz clock resolution limit inherent
> > > in detailed timings.
> > >
> > > drm_match_cea_mode() uses the normal KHZ2PICOS() matching of clocks,
> > > which only allows smaller errors for lower clocks (eg. for 25200 it
> > > won't allow any error) and a bigger error for higher clocks (eg. for
> > > 297000 it actually matches 296913-297000). So it doesn't really match
> > > what we want for the fixup. Using the explicit +-5kHz is much better
> > > for this use case.
> > >
> > > Not sure if we should change the normal mode matching to also use
> > > something else besides KHZ2PICOS() since it allows a different
> > > proportion of error depending on the clock. I believe VESA CVT
> > > allows a maximum deviation of .5%, so using that for normal mode
> > > matching might be a good idea?
> >
> > Ping. Any thoughts from anyone?
>
> Reviewed-by: Adam Jackson <ajax@redhat.com>
Applied to drm-misc, thanks for patch&review.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
prev parent reply other threads:[~2015-12-01 6:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-16 19:05 [PATCH] drm/edid: Make the detailed timing CEA/HDMI mode fixup accept up to 5kHz clock difference ville.syrjala
2015-11-26 17:01 ` Ville Syrjälä
2015-11-30 18:02 ` Adam Jackson
2015-12-01 6:57 ` Daniel Vetter [this message]
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=20151201065746.GB17050@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=ajax@redhat.com \
--cc=dri-devel@lists.freedesktop.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