[PATCHv2 19/22] drm/bridge: tc358767: copy the mode data, instead of storing the pointer

[Tomi Valkeinen]

On 15/04/2019 13:09, Andrzej Hajda wrote:
> On 26.03.2019 11:31, Tomi Valkeinen wrote:
>> In tc_bridge_mode_set callback, we store the pointer to the given
>> drm_display_mode, and use the mode later. Storing a pointer in such a
>> way looks very suspicious to me, and I have observed odd issues where
>> the timings were apparently (at least mostly) zero.
>>
>> Do a copy of the drm_display_mode instead to ensure we don't refer to
>> freed/modified data.
> 
> 
> Why not tc->bridge.encoder->crtc->state->adjusted_mode or
> 
> tc->bridge.encoder->crtc->state->mode ?
> 
> 
> They should exists if the mode is set.

Well, one reason was that my main concern was to get the DP output
working (as it was quite broken wrt. the link setup), and I wanted to
minimize all the other changes. This change felt the simplest way to fix
this issue and get forward, without possibly causing new problems.

Second, I'm a bit confused about DRM mode setting, and didn't want to
possibly move the driver into the wrong direction. It's not clear to me
whether the "mode" referred here is about the input or the output mode.
And, in both cases, if there's a bridge between the CRTC and the
TC358767, we would definitely be looking at the wrong mode if we peek at
the CRTC's.

 Tomi

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