Re: [PATCH] thunderbolt: Fix connection issue with Pluggable UD-4VPD dock

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi Greg,

On Tue, Nov 05, 2024 at 10:17:43AM +0100, Greg KH wrote:
> On Tue, Nov 05, 2024 at 10:53:01AM +0200, Mika Westerberg wrote:
> > Rick reported that his Pluggable USB4 dock does not work anymore after
> > 6.6.28 kernel.
> > 
> > It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband
> > access polling delay") makes the device router enumeration happen later
> > than what might be expected by the dock (although there is no such limit
> > in the USB4 spec) which probably makes it assume there is something
> > wrong with the high-speed link and reset it. After the link is reset the
> > same issue happens again and again.
> > 
> > For this reason lower the sideband access delay from 5ms to 1ms. This
> > seems to work fine according to Rick's testing.
> > 
> > Reported-by: Rick Lahaye <rick@581238.xyz>
> > Closes: https://lore.kernel.org/linux-usb/000f01db247b$d10e1520$732a3f60$@581238.xyz/
> > Tested-by: Rick Lahaye <rick@581238.xyz>
> > Fixes: c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
> 
> This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so
> how does this resolve an issue in the 6.6.y tree?

This refers to a mainline commit that caused the issue. The 6.6.28 is
the kernel version Rick used where it still worked. In other words, this
is not a backport of a fix but a fix intented to the mainline ;-) I hope
this clarifies. I can adjust the commit message if needed.