On Thu, 09 Sep 2021, Douglas Anderson <dianders@xxxxxxxxxxxx> wrote:
> A future change wants to be able to read just block 0 of the EDID, so
> break it out of drm_do_get_edid() into a sub-function.
>
> This is intended to be a no-op change--just code movement.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
>
> Changes in v4:
> - "u8 *edid" => "void *edid" to avoid cast.
> - Don't put kmalloc() in the "if" test even if the old code did.
> - drm_do_get_edid_blk0() => drm_do_get_edid_base_block()
>
> drivers/gpu/drm/drm_edid.c | 63 +++++++++++++++++++++++++++-----------
> 1 file changed, 45 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 6325877c5fd6..520fe1391769 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1905,6 +1905,44 @@ int drm_add_override_edid_modes(struct drm_connector *connector)
> }
> EXPORT_SYMBOL(drm_add_override_edid_modes);
>
> +static struct edid *drm_do_get_edid_base_block(
> + int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
> + size_t len),
> + void *data, bool *edid_corrupt, int *null_edid_counter)
> +{
> + int i;
> + void *edid;
> +
> + edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
> + if (edid == NULL)
> + return NULL;
> +
> + /* base block fetch */
> + for (i = 0; i < 4; i++) {
> + if (get_edid_block(data, edid, 0, EDID_LENGTH))
> + goto out;
> + if (drm_edid_block_valid(edid, 0, false, edid_corrupt))
> + break;
> + if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
> + if (null_edid_counter)
> + (*null_edid_counter)++;
> + goto carp;
> + }
> + }
> + if (i == 4)
> + goto carp;
> +
> + return edid;
> +
> +carp:
> + kfree(edid);
> + return ERR_PTR(-EINVAL);
> +
> +out:
> + kfree(edid);
> + return NULL;
> +}
> +
> /**
> * drm_do_get_edid - get EDID data using a custom EDID block read function
> * @connector: connector we're probing
> @@ -1938,25 +1976,16 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
> if (override)
> return override;
>
> - if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
> + edid = (u8 *)drm_do_get_edid_base_block(get_edid_block, data,
> + &connector->edid_corrupt,
> + &connector->null_edid_counter);
> + if (IS_ERR_OR_NULL(edid)) {
> + if (IS_ERR(edid))
> + connector_bad_edid(connector, edid, 1);
> return NULL;
> -
> - /* base block fetch */
> - for (i = 0; i < 4; i++) {
> - if (get_edid_block(data, edid, 0, EDID_LENGTH))
> - goto out;
> - if (drm_edid_block_valid(edid, 0, false,
> - &connector->edid_corrupt))
> - break;
> - if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
> - connector->null_edid_counter++;
> - goto carp;
> - }
> }
> - if (i == 4)
> - goto carp;
>
> - /* if there's no extensions, we're done */
> + /* if there's no extensions or no connector, we're done */
> valid_extensions = edid[0x7e];
> if (valid_extensions == 0)
> return (struct edid *)edid;
> @@ -2010,8 +2039,6 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
>
> return (struct edid *)edid;
>
> -carp:
> - connector_bad_edid(connector, edid, 1);
> out:
> kfree(edid);
> return NULL;
--
Jani Nikula, Intel Open Source Graphics Center
