lkml.org 
[lkml]   [2011]   [Jul]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH 1/3] drm: Separate EDID Header Check from EDID Block Check
    From
    On Wed, Jul 6, 2011 at 7:30 PM,  <reimth@googlemail.com> wrote:
    > From: Thomas Reim <rdratlos@yahoo.co.uk>
    >
    >    Provides function drm_edid_header_is_valid() for EDID header check
    >    and replaces EDID header check part of function drm_edid_block_valid()
    >    by a call of drm_edid_header_is_valid().
    >    This is a prerequisite to extend DDC probing, e. g. in function
    >    radeon_ddc_probe() for Radeon devices, by a central EDID header check.
    >
    >    Tested for kernel 2.35, 2.38 and 3.0
    >
    > Signed-off-by: Thomas Reim <rdratlos@yahoo.co.uk>

    Reviewed-by: Alex Deucher <alexdeucher@gmail.com>

    > ---
    >  drivers/gpu/drm/drm_edid.c |   24 ++++++++++++++++++------
    >  include/drm/drm_crtc.h     |    1 +
    >  2 files changed, 19 insertions(+), 6 deletions(-)
    >
    > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
    > index 0929219..1bbb85b 100644
    > --- a/drivers/gpu/drm/drm_edid.c
    > +++ b/drivers/gpu/drm/drm_edid.c
    > @@ -127,6 +127,23 @@ static const u8 edid_header[] = {
    >        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
    >  };
    >
    > + /*
    > + * Sanity check the header of the base EDID block.  Return 8 if the header
    > + * is perfect, down to 0 if it's totally wrong.
    > + */
    > +int drm_edid_header_is_valid(const u8 *raw_edid)
    > +{
    > +       int i, score = 0;
    > +
    > +       for (i = 0; i < sizeof(edid_header); i++)
    > +               if (raw_edid[i] == edid_header[i])
    > +                       score++;
    > +
    > +       return score;
    > +}
    > +EXPORT_SYMBOL(drm_edid_header_is_valid);
    > +
    > +
    >  /*
    >  * Sanity check the EDID block (base or extension).  Return 0 if the block
    >  * doesn't check out, or 1 if it's valid.
    > @@ -139,12 +156,7 @@ drm_edid_block_valid(u8 *raw_edid)
    >        struct edid *edid = (struct edid *)raw_edid;
    >
    >        if (raw_edid[0] == 0x00) {
    > -               int score = 0;
    > -
    > -               for (i = 0; i < sizeof(edid_header); i++)
    > -                       if (raw_edid[i] == edid_header[i])
    > -                               score++;
    > -
    > +               int score = drm_edid_header_is_valid(raw_edid);
    >                if (score == 8) ;
    >                else if (score >= 6) {
    >                        DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
    > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
    > index 33d12f8..0ec3687 100644
    > --- a/include/drm/drm_crtc.h
    > +++ b/include/drm/drm_crtc.h
    > @@ -802,6 +802,7 @@ extern struct drm_display_mode *drm_gtf_mode_complex(struct drm_device *dev,
    >  extern int drm_add_modes_noedid(struct drm_connector *connector,
    >                                int hdisplay, int vdisplay);
    >
    > +extern int drm_edid_header_is_valid(const u8 *raw_edid);
    >  extern bool drm_edid_is_valid(struct edid *edid);
    >  struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
    >                                           int hsize, int vsize, int fresh);
    > --
    > 1.7.1
    >
    >
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2011-07-07 16:01    [W:0.025 / U:63.560 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site