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

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jul 12, 2023 at 11:33:58AM +0530, Sanjay R Mehta wrote:
> 
> 
> On 7/12/2023 11:23 AM, Greg KH wrote:
> > On Wed, Jul 12, 2023 at 12:32:26AM -0500, Sanjay R Mehta wrote:
> >> From: Sanjay R Mehta <sanju.mehta@amd.com>
> >>
> >> 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.
> >>
> >> Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
> >> Signed-off-by: Sanath S <Sanath.S@amd.com>
> >> ---
> >>  drivers/thunderbolt/tmu.c | 4 +++-
> >>  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > Why is this a RESEND?  What changed?
> > 
> > And the ordering of the signed-off-by is incorrect.
> > 
> Hi Greg, My Apologies, but am unable to comprehend what I should be
> doing here. Please guide me on this.

Please go and take the AMD kernel developer class/training/something and
work with internal developers to get this right before resending it
again.

thanks,

greg k-h