[Intel-gfx] [PATCH v3 3/3] drm: clean cached display info

[Sharma, Shashank]

Regards

Shashank


On 12/29/2016 3:35 PM, Jose Abreu wrote:
> Hi Shashank,
>
>
> On 29-12-2016 05:53, Sharma, Shashank wrote:
>> Regards
>>
>> Shashank
>>
>>
>> On 12/27/2016 3:07 PM, Daniel Vetter wrote:
>>> On Thu, Dec 22, 2016 at 10:21:25AM +0000, Jose Abreu wrote:
>>>> Hi Shashank,
>>>>
>>>>
>>>> On 21-12-2016 15:29, Shashank Sharma wrote:
>>>>> This patch adds a small helper function, which clears the
>>>>> cached
>>>>> information about a hot-pluggable display, from connector.
>>>>> On event
>>>>> This will run on event of a hot-unplug, keeping the
>>>>> connector's display
>>>>> info up-to-date, avoiding any errors due to invalid cached
>>>>> data.
>>>>>
>>>>> Cc: Jose Abreu <joabreu at synopsys.com>
>>>>>
>>>>> Suggested-by: Jose Abreu <joabreu at synopsys.com>
>>>>> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
>>>>> ---
>>>>>    drivers/gpu/drm/drm_probe_helper.c | 20 ++++++++++++++++++++
>>>>>    1 file changed, 20 insertions(+)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/drm_probe_helper.c
>>>>> b/drivers/gpu/drm/drm_probe_helper.c
>>>>> index 7cff91e..9e97b45 100644
>>>>> --- a/drivers/gpu/drm/drm_probe_helper.c
>>>>> +++ b/drivers/gpu/drm/drm_probe_helper.c
>>>>> @@ -164,6 +164,18 @@ void
>>>>> drm_kms_helper_poll_enable_locked(struct drm_device *dev)
>>>>>    }
>>>>>      /**
>>>>> + * drm_helper_clear_display_info - clean cached display
>>>>> information for
>>>>> + * hot pluggable displays, on event of hot-unplug
>>>>> + * @connector: connector under event
>>>>> + */
>>>>> +void drm_helper_clear_display_info(struct drm_connector
>>>>> *connector)
>>>>> +{
>>>>> +    struct drm_display_info *info = &connector->display_info;
>>>>> +
>>>>> +    memset(info, 0, sizeof(*info));
>>>>> +}
>>>>> +
>>>>> +/**
>>>>>     * drm_helper_probe_single_connector_modes - get complete
>>>>> set of display modes
>>>>>     * @connector: connector to probe
>>>>>     * @maxX: max width for modes
>>>>> @@ -288,6 +300,14 @@ int
>>>>> drm_helper_probe_single_connector_modes(struct drm_connector
>>>>> *connector,
>>>>>            DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
>>>>>                connector->base.id, connector->name);
>>>>>            drm_mode_connector_update_edid_property(connector,
>>>>> NULL);
>>>>> +
>>>>> +        /*
>>>>> +         * Connector status change to disconnected, time to
>>>>> clean
>>>>> +         * cached display information
>>>>> +         */
>>>>> +        if (connector->status ==
>>>>> connector_status_disconnected)
>>>>> +            drm_helper_clear_display_info(connector);
>>>>> +
>>>> I don't know if this is the right place to do this because it is
>>>> a helper and I don't know if it is used by all the drivers. We
>>>> may need something more general that is always called when
>>>> probing modes, or force drivers that don't use the helper to use
>>>> the drm_helper_clear_display_info function. As I told you
>>>> before,
>>>> I'm new to dri-devel so we need more comments.
>>> Seems reasonable to me, since afaik all drivers do use the
>>> probe helpers.
>>> -Daniel
>> This was my understanding too. Jose, you think there would be
>> any drivers who dont use this probe ?
>> - Shashank
> I found only one driver that don't use this helper: vmwgfx. But,
> this driver does not seem to use EDID fields, it has a list of
> preferred video modes and manually adds these modes.
>
> So, I think it is safe to add this in the helper as long as
> future drivers that use EDID use this helper also. Maybe a small
> comment about this should be added in the helper declaration.
>
> Best regards,
> Jose Miguel Abreu
Sure, I will add a comment and publish a new patchset.
Shashank
>>>> Best regards,
>>>> Jose Miguel Abreu
>>>>
>>>>>            verbose_prune = false;
>>>>>            goto prune;
>>>>>        }
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