[PATCHv2 14/22] drm/bridge: tc358767: cleanup LT result check

[Tomi Valkeinen]

On 21/04/2019 01:06, Laurent Pinchart wrote:
> Hi Tomi,
> 
> Thank you for the patch.
> 
> On Tue, Mar 26, 2019 at 12:31:38PM +0200, Tomi Valkeinen wrote:
>> The driver has a loop after ending link training, where it reads the
>> DPCD link status and prints an error if that status is not ok.
>>
>> The loop is unnecessary, as far as I can understand from DP specs, so
>> let's remove it. We can also print the more specific errors to help
>> debugging.
> 
> I see in tc_link_training() that the driver checks the channel EQ bits
> through the TC358767 DP0_LTSTAT register. Does the chip read the link
> status DPCD registers by itself through the AUX link ? If so we could

Yes. I'm not exactly sure at what point TC358767 reads the registers,
but I think it reads it at the end of link training loop. In theory the
link should stay up after that, but as described in the previous patch,
that was not what I saw in every case. So I'd rather have an explicit
check here at the end.

 Tomi

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