On Wed, Feb 28, 2024 at 4:21 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> Hi,
>
> On Tue, Feb 27, 2024 at 5:11 PM Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> wrote:
> >
> > Some panels are interested in the EDID during early probe when connector
> > is still unknown.
> >
> > Add a function drm_get_edid_no_connector() to get edid without connector.
> > No functional change for existing usage.
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> > ---
> > v1->v2:
> > add a function to return the entire edid without updating connector.
> > ---
> > drivers/gpu/drm/drm_edid.c | 45 ++++++++++++++++++++++++++++----------
> > include/drm/drm_edid.h | 1 +
> > 2 files changed, 34 insertions(+), 12 deletions(-)
>
> I'll respond in the discussion in v1 too, but overall I'm not a fan of
> reading the whole EDID twice at bootup. Personally I'd love to see us
> to back to just reading the base block like in v1, but I guess we can
> see what Jani and others say.
>
>
> > @@ -2385,18 +2385,20 @@ static struct edid *_drm_do_get_edid(struct drm_connector *connector,
> > if (status == EDID_BLOCK_READ_FAIL)
> > goto fail;
> >
> > - /* FIXME: Clarify what a corrupt EDID actually means. */
> > - if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> > - connector->edid_corrupt = false;
> > - else
> > - connector->edid_corrupt = true;
> > + if (connector) {
> > + /* FIXME: Clarify what a corrupt EDID actually means. */
> > + if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> > + connector->edid_corrupt = false;
> > + else
> > + connector->edid_corrupt = true;
> >
> > - if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> > - if (status == EDID_BLOCK_ZERO)
> > - connector->null_edid_counter++;
> > + if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> > + if (status == EDID_BLOCK_ZERO)
> > + connector->null_edid_counter++;
> >
> > - connector_bad_edid(connector, edid, 1);
> > - goto fail;
> > + connector_bad_edid(connector, edid, 1);
> > + goto fail;
>
> This "goto fail" is now only run "if (connector)" which means that
> you're not properly checking if the EDID is valid when "connector ==
> NULL", right? That seems like a bug unless I missed something...
We can't check with connector_bad_edid() since there's no connector.
But we still check with edid_block_read() status, similar to what the
original drm_edid_get_panel_id() checks.
