On Wed, Aug 23, 2023 at 02:18:25PM -0500, Mario Limonciello wrote:
> From: Sanjay R Mehta <sanju.mehta@xxxxxxx>
>
> 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@xxxxxxx>
> Signed-off-by: Sanath S <Sanath.S@xxxxxxx>
> Signed-off-by: Sanjay R Mehta <sanju.mehta@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> (cherry picked from commit 583893a66d731f5da010a3fa38a0460e05f0149b)
>
> USB4v2 introduced support for uni-directional TMU mode as part of
> d49b4f043d63 ("thunderbolt: Add support for enhanced uni-directional TMU mode")
> This is not a stable candidate commit, so adjust the code for backport.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Both now applied, thanks.
greg k-h
