[PATCH 1/2] Enhances EDID quirks to allow for specifying and preferring a mode not reported in the EDID block.

[Alex Deucher]

On Thu, Mar 21, 2013 at 5:36 PM, Dylan Semler <dylan.semler at gmail.com> wrote:
>
> Signed-off-by: Dylan Semler <dylan.semler at gmail.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 72 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index c194f4e..b1036b5 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -68,6 +68,8 @@
>  #define EDID_QUIRK_DETAILED_SYNC_PP            (1 << 6)
>  /* Force reduced-blanking timings for detailed modes */
>  #define EDID_QUIRK_FORCE_REDUCED_BLANKING      (1 << 7)
> +/* Force specific mode for monitors that don't report correct EDIDs */
> +#define EDID_QUIRK_FORCE_MODE                  (1 << 8)
>
>  struct detailed_mode_closure {
>         struct drm_connector *connector;
> @@ -127,6 +129,15 @@ static struct edid_quirk {
>         { "VSC", 5020, EDID_QUIRK_FORCE_REDUCED_BLANKING },
>  };
>
> +static struct edid_quirk_force_mode {
> +       char vendor[4];
> +       int product_id;
> +       int hdisplay;
> +       int vdisplay;
> +       int vrefresh;
> +} edid_quirk_force_mode_list[] = {
> +};
> +
>  /*
>   * Autogenerated from the DMT spec.
>   * This table is copied from xfree86/modes/xf86EdidModes.c.
> @@ -2219,6 +2230,65 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
>         return closure.modes;
>  }
>
> +/* Add an explicit mode based on a quirk
> + */
> +static int
> +do_force_quirk_modes(struct drm_connector *connector, int hdisplay,
> +                    int vdisplay, int vrefresh)
> +{
> +       struct drm_display_mode *mode;
> +       struct drm_device *dev = connector->dev;
> +       int num_modes = 0;
> +
> +       /* sanity check display parameters */
> +       if (hdisplay < 0)
> +               return 0;
> +       if (vdisplay < 0)
> +               return 0;
> +       if (vrefresh < 0)
> +               return 0;
> +
> +       mode = drm_gtf_mode(dev, hdisplay, vdisplay, vrefresh, 0, 0);

I would suggest using drm_cvt_mode() here since most modern monitors
prefer cvt timing and usually reduced blanking.  A lot of LCD monitors
don't like gtf timing.  You might also want to add a reduced blanking
field to the edid_quirk_force_mode struct so that you can specify on a
quirk by quirk basis.

Alex

> +
> +       if (mode) {
> +               mode->type |= DRM_MODE_TYPE_PREFERRED;
> +               drm_mode_probed_add(connector, mode);
> +               num_modes++;
> +       }
> +       return num_modes;
> +}
> +
> +/*
> + * add_force_quirk_modes - Add modes based on monitor's EDID quirks
> + * @connector: attached connector
> + * @edid: EDID block to scan
> + * @quirks: quirks to apply
> + *
> + * At least one monitor doesn't report its native resolution in its EDID block.
> + * Here we add the native mode according to this quirk
> + */
> +static int
> +add_force_quirk_modes(struct drm_connector *connector, struct edid *edid,
> +                     u32 quirks)
> +{
> +       struct edid_quirk_force_mode *quirk_mode;
> +       int i, num_modes = 0;
> +
> +       for (i = 0; i < ARRAY_SIZE(edid_quirk_force_mode_list); i++) {
> +               quirk_mode = &edid_quirk_force_mode_list[i];
> +
> +               if (edid_vendor(edid, quirk_mode->vendor) &&
> +                   (EDID_PRODUCT_ID(edid) == quirk_mode->product_id)) {
> +                       num_modes = do_force_quirk_modes(connector,
> +                                       quirk_mode->hdisplay,
> +                                       quirk_mode->vdisplay,
> +                                       quirk_mode->vrefresh);
> +               }
> +       }
> +       return num_modes;
> +
> +}
> +
>  #define HDMI_IDENTIFIER 0x000C03
>  #define AUDIO_BLOCK    0x01
>  #define VIDEO_BLOCK     0x02
> @@ -2803,6 +2873,8 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
>
>         if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
>                 edid_fixup_preferred(connector, quirks);
> +       if (quirks & EDID_QUIRK_FORCE_MODE)
> +               num_modes += add_force_quirk_modes(connector, edid, quirks);
>
>         drm_add_display_info(edid, &connector->display_info);
>
> --
> 1.7.11.7
>
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