Re: [PATCH] drm/msm: Initialize mode_config earlier

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 13/01/2023 06:23, Dmitry Baryshkov wrote:
> On 13/01/2023 06:10, Bjorn Andersson wrote:
>> Invoking drm_bridge_hpd_notify() on a drm_bridge with a HPD-enabled
>> bridge_connector ends up in drm_bridge_connector_hpd_cb() calling
>> drm_kms_helper_hotplug_event(), which assumes that the associated
>> drm_device's mode_config.funcs is a valid pointer.
>>
>> But in the MSM DisplayPort driver the HPD enablement happens at bind
>> time and mode_config.funcs is initialized late in msm_drm_init(). This
>> means that there's a window for hot plug events to dereference a NULL
>> mode_config.funcs.
>>
>> Move the assignment of mode_config.funcs before the bind, to avoid this
>> scenario.
> 
> Cam we make DP driver not to report HPD events until the enable_hpd() 
> was called? I think this is what was fixed by your internal_hpd patchset.

Or to express this in another words: I thought that internal_hpd already 
deferred enabling hpd event reporting till the time when we need it, 
didn't it?


-- 
With best wishes
Dmitry