Re: [PATCH V2] thunderbolt: Fix Thunderbolt 3 display flickering issue on 2nd hot plug onwards

[Sanjay R Mehta <sanmehta@amd.com>]

On 7/31/2023 8:24 PM, Mika Westerberg wrote:
> On Mon, Jul 31, 2023 at 06:37:16PM +0530, Sanjay R Mehta wrote:
>>
>>
>> On 7/31/2023 4:45 PM, Mika Westerberg wrote:
>>> On Wed, Jul 12, 2023 at 01:16:19PM -0500, Sanjay R Mehta wrote:
>>>> Previously, on unplug events, the TMU mode was disabled first
>>>> followed by the Time Synchronization Handshake, irrespective of
>>>> whether the tb_switch_tmu_rate_write() API was successful or not.
>>>>
>>>> However, this caused a problem with Thunderbolt 3 (TBT3)
>>>> devices, as the TSPacketInterval bits were always enabled by default,
>>>> leading the host router to assume that the device router's TMU was
>>>> already enabled and preventing it from initiating the Time
>>>> Synchronization Handshake. As a result, TBT3 monitors experienced
>>>> display flickering from the second hot plug onwards.
>>>>
>>>> To address this issue, we have modified the code to only disable the
>>>> Time Synchronization Handshake during TMU disable if the
>>>> tb_switch_tmu_rate_write() function is successful. This ensures that
>>>> the TBT3 devices function correctly and eliminates the display
>>>> flickering issue.
>>>>
>>>> Co-developed-by: Sanath S <Sanath.S@amd.com>
>>>> Signed-off-by: Sanath S <Sanath.S@amd.com>
>>>> Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
>>>
>>> Looks good.
>>>
>>> I suppose you want this in -stable too, right?
>>
>> Thanks. Yes Mika.
> 
> Hm, I get:
> 
> Applying: thunderbolt: Fix Thunderbolt 3 display flickering issue on 2nd hot plug onwards
> error: patch failed: drivers/thunderbolt/tmu.c:415
> error: drivers/thunderbolt/tmu.c: patch does not apply
> Patch failed at 0001 thunderbolt: Fix Thunderbolt 3 display flickering issue on 2nd hot plug onwards
> 
> Is this based on v6.5-rcX or something else?

Hi Mika, This patch was tested a month ago and built on top of 6.4..
I'll resend based on latest. Apologies for the inconvenience..

- Sanjay