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

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Nov 05, 2024 at 11:24:12AM +0200, Mika Westerberg wrote:
> 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.

Ah, yeah, that is confusing so rewording it might be good as the
offending kernel is really 6.10, not 6.6.

Also, do you want me to take this in my tree now when you resend it, or
do you want to send it with other changes later?

thanks,

greg k-h