Re: [PATCH v3 1/3] drm/edid: Add drm_edid_get_monitor_name()

Jani Nikula
2016-04-12T09:30:47Z

On Mon, 11 Apr 2016, Jim Bride <jim.bride@linux.intel.com> wrote:
> In order to include monitor name information in debugfs
> output we needed to add a function that would extract the
> monitor name from the EDID, and that function needed to
> reside in the file where the rest of the EDID helper
> functions are implemented.
>
> v2: Refactor to have drm_edid_get_monitor_name() and drm_edid_to_eld()
> use a common helper function to extract the monitor name from the
> edid. [Jani] + rebase.
>
> v3: Minor changes suggested by Jani + rebase.
>
> cc: dri-devel@lists.freedesktop.org
> cc: Jani Nikula <jani.nikula@linux.intel.com>
> Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
> ---
> drivers/gpu/drm/drm_edid.c | 51 ++++++++++++++++++++++++++++++++++++++--------
> include/drm/drm_crtc.h | 2 ++
> 2 files changed, 44 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 558ef9f..da30ce3 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3293,6 +3293,46 @@ monitor_name(struct detailed_timing *t, void *data)
> *(u8 **)data = t->data.other_data.data.str.str;
> }
>
> +static int get_monitor_name(struct edid *edid, char name[13])
> +{
> + char *edid_name = NULL;
> + int mnl;
> +
> + if (!edid || !name)
> + return 0;
> +
> + drm_for_each_detailed_block((u8 *)edid, monitor_name, &edid_name);
> + for (mnl = 0; edid_name && mnl < 13; mnl++) {
> + if (edid_name[mnl] == 0x0a)
> + break;
> +
> + name[mnl] = edid_name[mnl];
> + }
> +
> + return mnl;
> +}
> +
> +/**
> + * drm_edid_get_monitor_name - fetch the monitor name from the edid
> + * @edid: monitor EDID information
> + * @name: pointer to a character array to hold the name of the monitor
> + * @bufsize: The size of the name buffer (should be at least 13 chars.)

Nitpick, should be 13 + termination = 14 bytes.

> + *
> + */
> +void drm_edid_get_monitor_name(struct edid *edid, char *name, int bufsize)
> +{
> + int name_length = -1;

Nitpick, no need to initialize.

Other than those,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> + char buf[13];
> +
> + if (bufsize <= 0)
> + return;
> +
> + name_length = min(get_monitor_name(edid, buf), bufsize - 1);
> + memcpy(name, buf, name_length);
> + name[name_length] = '\0';
> +}
> +EXPORT_SYMBOL(drm_edid_get_monitor_name);
> +
> /**
> * drm_edid_to_eld - build ELD from EDID
> * @connector: connector corresponding to the HDMI/DP sink
> @@ -3306,7 +3346,6 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> {
> uint8_t *eld = connector->eld;
> u8 *cea;
> - u8 *name;
> u8 *db;
> int total_sad_count = 0;
> int mnl;
> @@ -3320,14 +3359,8 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> return;
> }
>
> - name = NULL;
> - drm_for_each_detailed_block((u8 *)edid, monitor_name, &name);
> - /* max: 13 bytes EDID, 16 bytes ELD */
> - for (mnl = 0; name && mnl < 13; mnl++) {
> - if (name[mnl] == 0x0a)
> - break;
> - eld[20 + mnl] = name[mnl];
> - }
> + mnl = get_monitor_name(edid, eld + 20);
> +
> eld[4] = (cea[1] << 5) | mnl;
> DRM_DEBUG_KMS("ELD monitor %s\n", eld + 20);
>
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 8cb377c..6d46842 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -2500,6 +2500,8 @@ extern int drm_edid_header_is_valid(const u8 *raw_edid);
> extern bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid,
> bool *edid_corrupt);
> extern bool drm_edid_is_valid(struct edid *edid);
> +extern void drm_edid_get_monitor_name(struct edid *edid, char *name,
> + int buflen);
>
> extern struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
> char topology[8]);

--
Jani Nikula, Intel Open Source Technology Center