[PATCHv2 10/22] drm/bridge: tc358767: add link disable function

[Tomi Valkeinen]

On 15/04/2019 11:36, Andrzej Hajda wrote:

>> +static int tc_main_link_disable(struct tc_data *tc)
>> +{
>> +	int ret;
>> +
>> +	dev_dbg(tc->dev, "link disable\n");
>> +
>> +	tc_write(DP0_SRCCTRL, 0);
>> +	tc_write(DP0CTL, 0);
> 
> 
> The same register is set in stream_disable, is it correct? Looks
> suspicious, disabling stream and link should be different things.

Good point. It's probably not correct. With these patches, the link and
stream are always enabled and disabled together, so it shouldn't cause
any problems at the moment.

During my debugging and development, at some point I had a version where
I enabled the link right away when we got HPD high, mostly to help my
debugging. That's why I separated link and stream setup (although I
think that's a logical design in any case).

However, I never did try disabling only stream, and keeping the link up,
so it may well be non-functional. Or, well, it clearly is
non-functional, as we disable the link (DP0CTL) in tc_stream_disable()...

So this is mostly about just adding the architecture to have separate
link/stream handling, but the functionality is not there. I should
perhaps add a comment to the code to point this out.

 Tomi

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