On Thu, 12 Sep 2024, Thomas Zimmermann <tzimmermann@xxxxxxx> wrote: > Hi > > Am 12.09.24 um 10:48 schrieb Jani Nikula: >> On Thu, 12 Sep 2024, Thomas Zimmermann <tzimmermann@xxxxxxx> 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 The problem is that the entire logic is outdated.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. > > With drm_connector_helper_detect_from_ddc() there is already a helper > for detection. It makes sense to use it. And if we continue to update > the properties in detect (instead of get_modes), what is the correct > connector_status on errors? Right now and with the patch applied, detect > returns status_disconnected on errors. But this isn't correct if there > actually is a display. By separating detect and get_modes cleanly, we > can detect the display reliably, but also handle errors better than we > currently do in gma500. Get_modes is already expected to update the EDID > property, [1] for detect it's not so clear AFAICT. I think that from a > design perspective, it makes sense to have a read-only function that > only detects the physical state of the connector and a read-write > function that updates the connector's properties. Best regards Thomas > [1] > https://elixir.bootlin.com/linux/v6.10.9/source/include/drm/drm_modeset_helper_vtables.h#L865 So what if you can probe DDC but can't actually read an EDID of any kind? IMO that's a detect failure. Or how about things like CEC attach? Seems natural to do it at .detect(). Doing it at .get_modes() just seems wrong. However, it needs the EDID for physical address. I just don't think one size fits all here. BR, Jani. > >> >> I think it should be fine to do incremental refactors like the patch at >> hand (modulo some issues I mention below). >> >> BR, >> Jani. >> >> >>> Do you have a device for testing such a change? >>> >>> Best regards >>> Thomas >>> >>>> Signed-off-by: Tejas Vipin <tejasvipin76@xxxxxxxxx> >>>> --- >>>> Changes in v2: >>>> - Use drm_edid instead of edid >>>> >>>> Link to v1: https://lore.kernel.org/all/20240910051856.700210-1-tejasvipin76@xxxxxxxxx/ >>>> --- >>>> 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
