From: Daniel Vetter <daniel@ffwll.ch>
To: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
intel-gfx@lists.freedesktop.org,
Daniel Stone <daniels@collabora.com>,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm: fix lut value extraction function
Date: Mon, 18 Apr 2016 14:36:39 +0200 [thread overview]
Message-ID: <20160418123639.GD2510@phenom.ffwll.local> (raw)
In-Reply-To: <5714C07F.3050807@intel.com>
On Mon, Apr 18, 2016 at 12:09:51PM +0100, Lionel Landwerlin wrote:
> Ping?
>
> On 22/03/16 14:10, Lionel Landwerlin wrote:
> >When extracting the value at full precision (16 bits), no need to
> >round the value.
> >
> >This was spotted by Jani when running sparse. Unfortunately this fix
> >doesn't get rid of the warning.
It sounded like no bug, and the patch itself fails to appease sparse. And
I didn't check what's upsetting sparse itself, so figured "nothing to do
here until a real fix shows up".
Should I do something here?
-Daniel
> >
> >Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> >Reported-by: Jani Nikula <jani.nikula@intel.com>
> >Cc: Daniel Stone <daniels@collabora.com>
> >Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> >Cc: Matt Roper <matthew.d.roper@intel.com>
> >Cc: dri-devel@lists.freedesktop.org
> >Fixes: 5488dc16fde7 ("drm: introduce pipe color correction properties")
> >---
> > include/drm/drm_crtc.h | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> >diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> >index e0170bf..da63b4d 100644
> >--- a/include/drm/drm_crtc.h
> >+++ b/include/drm/drm_crtc.h
> >@@ -2600,10 +2600,14 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev,
> > static inline uint32_t drm_color_lut_extract(uint32_t user_input,
> > uint32_t bit_precision)
> > {
> >- uint32_t val = user_input + (1 << (16 - bit_precision - 1));
> >+ uint32_t val = user_input;
> > uint32_t max = 0xffff >> (16 - bit_precision);
> >- val >>= 16 - bit_precision;
> >+ /* Round only if we're not using full precision. */
> >+ if (bit_precision < 16) {
> >+ val += 1UL << (16 - bit_precision - 1);
> >+ val >>= 16 - bit_precision;
> >+ }
> > return clamp_val(val, 0, max);
> > }
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2016-04-18 12:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-22 14:10 [PATCH] drm: fix lut value extraction function Lionel Landwerlin
2016-04-18 11:09 ` Lionel Landwerlin
2016-04-18 12:36 ` Daniel Vetter [this message]
2016-04-18 14:40 ` Emil Velikov
2016-04-18 15:53 ` Daniel Vetter
2016-04-18 19:39 ` Emil Velikov
2016-04-20 10:52 ` Daniel Vetter
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=20160418123639.GD2510@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=daniel.vetter@ffwll.ch \
--cc=daniels@collabora.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=intel-gfx@lists.freedesktop.org \
--cc=lionel.g.landwerlin@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