On Wed, Dec 13, 2017 at 12:44:26AM -0800, Keith Packard wrote:
> There are a set of values in the drm_display_info structure for each
> connector which hold information derived from EDID. These are computed
> in drm_add_display_info. Before this patch, that was only called in
> drm_add_edid_modes. This meant that they were only set when EDID was
> present and never reset when EDID was not, as happened when the
> display was disconnected.
>
> One of these fields, non_desktop, is used from
> drm_mode_connector_update_edid_property, the function responsible for
> assigning the new edid value to the application-visible property.
>
> Various drivers call these two functions (drm_add_edid_modes and
> drm_mode_connector_update_edid_property) in different orders. This
> means that even when EDID is present, the drm_display_info fields may
> not have been computed at the time that
> drm_mode_connector_update_edid_property used the non_desktop value to
> set the non_desktop property.
>
> I've added a public function (drm_reset_display_info) that resets the
> drm_display_info field values to default values and then made the
> drm_add_display_info function public. These two functions are now
> called directly from drm_mode_connector_update_edid_property so that
> the drm_display_info fields are always computed from the current EDID
> information before being used in that function.
>
> This means that the drm_display_info values are often computed twice,
> once when the EDID property it set and a second time when EDID is used
> to compute modes for the device. The alternative would be to uniformly
> ensure that the values were computed once before being used, which
> would require that all drivers reliably invoke the two paths in the
> same order. The computation is inexpensive enough that it seems more
> maintainable in the long term to simply compute them in both paths.
>
> The API to drm_add_display_info has been changed so that it no longer
> takes the set of edid-based quirks as a parameter. Rather, it now
> computes those quirks itself and returns them for further use by
> drm_add_edid_modes.
>
> This patch also includes a number of 'const' additions caused by
> drm_mode_connector_update_edid_property taking a 'const struct edid *'
> parameter and wanting to pass that along to drm_add_display_info.
>
> v2: after review by Daniel Vetter <daniel.vetter@xxxxxxxx>
>
> Removed EXPORT_SYMBOL_GPL for drm_reset_display_info and
> drm_add_display_info.
>
> Added FIXME in drm_mode_connector_update_edid_property about
> potentially merging that with drm_add_edid_modes to avoid
> the need for two driver calls.
>
> Signed-off-by: Keith Packard <keithp@xxxxxxxxxx>
> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Ok there's a functional conflict when I tried to apply this to -fixes,
due to some rework already in drm-misc-next. Hence I applied your original
patch here to drm-misc-next, and then cherry-picked it over to
drm-misc-fixes and fixed it up. That way we'll not loose the bits needed
in -next.
Please double-check I didn't wreck stuff before I send the pull request
out.
Thanks, Daniel
> ---
> drivers/gpu/drm/drm_connector.c | 13 ++++++++++
> drivers/gpu/drm/drm_edid.c | 53 ++++++++++++++++++++++++++++++-----------
> include/drm/drm_edid.h | 2 ++
> 3 files changed, 54 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 25f4b2e9a44f..83c01f359d55 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -1207,6 +1207,19 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
> if (edid)
> size = EDID_LENGTH * (1 + edid->extensions);
>
> + /* Set the display info, using edid if available, otherwise
> + * reseting the values to defaults. This duplicates the work
> + * done in drm_add_edid_modes, but that function is not
> + * consistently called before this one in all drivers and the
> + * computation is cheap enough that it seems better to
> + * duplicate it rather than attempt to ensure some arbitrary
> + * ordering of calls.
> + */
> + if (edid)
> + drm_add_display_info(connector, edid);
> + else
> + drm_reset_display_info(connector);
> +
> drm_object_property_set_value(&connector->base,
> dev->mode_config.non_desktop_property,
> connector->display_info.non_desktop);
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 524eace3d460..365901c1c33c 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1731,7 +1731,7 @@ EXPORT_SYMBOL(drm_edid_duplicate);
> *
> * Returns true if @vendor is in @edid, false otherwise
> */
> -static bool edid_vendor(struct edid *edid, const char *vendor)
> +static bool edid_vendor(const struct edid *edid, const char *vendor)
> {
> char edid_vendor[3];
>
> @@ -1749,7 +1749,7 @@ static bool edid_vendor(struct edid *edid, const char *vendor)
> *
> * This tells subsequent routines what fixes they need to apply.
> */
> -static u32 edid_get_quirks(struct edid *edid)
> +static u32 edid_get_quirks(const struct edid *edid)
> {
> const struct edid_quirk *quirk;
> int i;
> @@ -2813,7 +2813,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
> /*
> * Search EDID for CEA extension block.
> */
> -static u8 *drm_find_edid_extension(struct edid *edid, int ext_id)
> +static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id)
> {
> u8 *edid_ext = NULL;
> int i;
> @@ -2835,12 +2835,12 @@ static u8 *drm_find_edid_extension(struct edid *edid, int ext_id)
> return edid_ext;
> }
>
> -static u8 *drm_find_cea_extension(struct edid *edid)
> +static u8 *drm_find_cea_extension(const struct edid *edid)
> {
> return drm_find_edid_extension(edid, CEA_EXT);
> }
>
> -static u8 *drm_find_displayid_extension(struct edid *edid)
> +static u8 *drm_find_displayid_extension(const struct edid *edid)
> {
> return drm_find_edid_extension(edid, DISPLAYID_EXT);
> }
> @@ -4378,7 +4378,7 @@ drm_parse_hdmi_vsdb_video(struct drm_connector *connector, const u8 *db)
> }
>
> static void drm_parse_cea_ext(struct drm_connector *connector,
> - struct edid *edid)
> + const struct edid *edid)
> {
> struct drm_display_info *info = &connector->display_info;
> const u8 *edid_ext;
> @@ -4412,11 +4412,34 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
> }
> }
>
> -static void drm_add_display_info(struct drm_connector *connector,
> - struct edid *edid, u32 quirks)
> +/* A connector has no EDID information, so we've got no EDID to compute quirks from. Reset
> + * all of the values which would have been set from EDID
> + */
> +void
> +drm_reset_display_info(struct drm_connector *connector)
> +{
> + struct drm_display_info *info = &connector->display_info;
> +
> + info->width_mm = 0;
> + info->height_mm = 0;
> +
> + info->bpc = 0;
> + info->color_formats = 0;
> + info->cea_rev = 0;
> + info->max_tmds_clock = 0;
> + info->dvi_dual = false;
> + info->has_hdmi_infoframe = false;
> +
> + info->non_desktop = 0;
> +}
> +EXPORT_SYMBOL_GPL(drm_reset_display_info);
> +
> +u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid)
> {
> struct drm_display_info *info = &connector->display_info;
>
> + u32 quirks = edid_get_quirks(edid);
> +
> info->width_mm = edid->width_cm * 10;
> info->height_mm = edid->height_cm * 10;
>
> @@ -4430,11 +4453,13 @@ static void drm_add_display_info(struct drm_connector *connector,
>
> info->non_desktop = !!(quirks & EDID_QUIRK_NON_DESKTOP);
>
> + DRM_DEBUG_KMS("non_desktop set to %d\n", info->non_desktop);
> +
> if (edid->revision < 3)
> - return;
> + return quirks;
>
> if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
> - return;
> + return quirks;
>
> drm_parse_cea_ext(connector, edid);
>
> @@ -4454,7 +4479,7 @@ static void drm_add_display_info(struct drm_connector *connector,
>
> /* Only defined for 1.4 with digital displays */
> if (edid->revision < 4)
> - return;
> + return quirks;
>
> switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
> case DRM_EDID_DIGITAL_DEPTH_6:
> @@ -4489,7 +4514,9 @@ static void drm_add_display_info(struct drm_connector *connector,
> info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
> if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB422)
> info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
> + return quirks;
> }
> +EXPORT_SYMBOL_GPL(drm_add_display_info);
>
> static int validate_displayid(u8 *displayid, int length, int idx)
> {
> @@ -4645,8 +4672,6 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
> return 0;
> }
>
> - quirks = edid_get_quirks(edid);
> -
> drm_edid_to_eld(connector, edid);
>
> /*
> @@ -4654,7 +4679,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
> * To avoid multiple parsing of same block, lets parse that map
> * from sink info, before parsing CEA modes.
> */
> - drm_add_display_info(connector, edid, quirks);
> + quirks = drm_add_display_info(connector, edid);
>
> /*
> * EDID spec says modes should be preferred in this order:
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index b25d12ef120a..8d89a9c3748d 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -465,6 +465,8 @@ struct edid *drm_get_edid(struct drm_connector *connector,
> struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
> struct i2c_adapter *adapter);
> struct edid *drm_edid_duplicate(const struct edid *edid);
> +void drm_reset_display_info(struct drm_connector *connector);
> +u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid);
> int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
>
> u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
> --
> 2.15.0.rc0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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