On Thu, 12 Sep 2024, Jani Nikula <jani.nik...@linux.intel.com> wrote:
> On Thu, 12 Sep 2024, Thomas Zimmermann <tzimmerm...@suse.de> wrote:
>> Hi
>>
>> Am 11.09.24 um 20:06 schrieb Tejas Vipin:
>>> Replace drm_detect_hdmi_monitor() with drm_display_info.is_hdmi since
>>> monitor HDMI information is available after EDID is parsed. Additionally
>>> rewrite the code the code to have fewer indentation levels.
>>
>> The problem is that the entire logic is outdated. The content 
>> of cdv_hdmi_detect() should go into cdv_hdmi_get_modes(), the detect_ctx 
>> callback should be set to drm_connector_helper_detect_from_ddc() and 
>> cdv_hdmi_detect() should be deleted. The result is that ->detect_ctx 
>> will detect the presence of a display and ->get_modes will update EDID 
>> and other properties.
>
> I guess I didn't get the memo on this one.
>
> What's the problem with reading the EDID at detect? The subsequent
> drm_edid_connector_add_modes() called from .get_modes() does not need to
> read the EDID again.

Moreover, in this case .detect() only detects digital displays as
reported by EDID. If you postpone that to .get_modes(), the probe helper
will still report connected, and invent non-EDID fallback modes. The
behaviour changes.

> I think it should be fine to do incremental refactors like the patch at
> hand (modulo some issues I mention below).

Another issue in the patch is that it should also change .get_modes() to
not read the EDID again, but just call drm_edid_connector_add_modes().

BR,
Jani.

>
> BR,
> Jani.
>
>
>>
>> Do you have  a device for testing such a change?
>>
>> Best regards
>> Thomas
>>
>>>
>>> Signed-off-by: Tejas Vipin <tejasvipi...@gmail.com>
>>> ---
>>> Changes in v2:
>>>      - Use drm_edid instead of edid
>>>
>>> Link to v1: 
>>> https://lore.kernel.org/all/20240910051856.700210-1-tejasvipi...@gmail.com/
>>> ---
>>>   drivers/gpu/drm/gma500/cdv_intel_hdmi.c | 24 +++++++++++++-----------
>>>   1 file changed, 13 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/gma500/cdv_intel_hdmi.c 
>>> b/drivers/gpu/drm/gma500/cdv_intel_hdmi.c
>>> index 2d95e0471291..701f8bbd5f2b 100644
>>> --- a/drivers/gpu/drm/gma500/cdv_intel_hdmi.c
>>> +++ b/drivers/gpu/drm/gma500/cdv_intel_hdmi.c
>>> @@ -128,23 +128,25 @@ static enum drm_connector_status cdv_hdmi_detect(
>>>   {
>>>     struct gma_encoder *gma_encoder = gma_attached_encoder(connector);
>>>     struct mid_intel_hdmi_priv *hdmi_priv = gma_encoder->dev_priv;
>>> -   struct edid *edid = NULL;
>>> +   const struct drm_edid *drm_edid;
>>> +   int ret;
>>>     enum drm_connector_status status = connector_status_disconnected;
>>>   
>>> -   edid = drm_get_edid(connector, connector->ddc);
>>> +   drm_edid = drm_edid_read_ddc(connector, connector->ddc);
>
> Just drm_edid_read() is enough when you're using connector->ddc.
>
>>> +   ret = drm_edid_connector_update(connector, drm_edid);
>>>   
>>>     hdmi_priv->has_hdmi_sink = false;
>>>     hdmi_priv->has_hdmi_audio = false;
>>> -   if (edid) {
>>> -           if (edid->input & DRM_EDID_INPUT_DIGITAL) {
>>> -                   status = connector_status_connected;
>>> -                   hdmi_priv->has_hdmi_sink =
>>> -                                           drm_detect_hdmi_monitor(edid);
>>> -                   hdmi_priv->has_hdmi_audio =
>>> -                                           drm_detect_monitor_audio(edid);
>>> -           }
>>> -           kfree(edid);
>>> +   if (ret)
>
> This error path leaks the EDID.
>
>>> +           return status;
>>> +
>>> +   if (drm_edid_is_digital(drm_edid)) {
>>> +           status = connector_status_connected;
>>> +           hdmi_priv->has_hdmi_sink = connector->display_info.is_hdmi;
>>> +           hdmi_priv->has_hdmi_audio = connector->display_info.has_audio;
>>>     }
>>> +   drm_edid_free(drm_edid);
>>> +
>>>     return status;
>>>   }
>>>   

-- 
Jani Nikula, Intel

Reply via email to