Re: [REGRESSION] thunderbolt: Fix a logic error in wake on connect

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sun, Jul 06, 2025 at 10:46:53AM -0400, Mario Limonciello wrote:
> On 6/30/25 07:32, Alyssa Ross wrote:
> > Alyssa Ross <hi@alyssa.is> writes:
> > 
> > > On Fri, Apr 11, 2025 at 10:14:44AM -0500, Mario Limonciello wrote:
> > > > From: Mario Limonciello <mario.limonciello@amd.com>
> > > > 
> > > > commit a5cfc9d65879c ("thunderbolt: Add wake on connect/disconnect
> > > > on USB4 ports") introduced a sysfs file to control wake up policy
> > > > for a given USB4 port that defaulted to disabled.
> > > > 
> > > > However when testing commit 4bfeea6ec1c02 ("thunderbolt: Use wake
> > > > on connect and disconnect over suspend") I found that it was working
> > > > even without making changes to the power/wakeup file (which defaults
> > > > to disabled). This is because of a logic error doing a bitwise or
> > > > of the wake-on-connect flag with device_may_wakeup() which should
> > > > have been a logical AND.
> > > > 
> > > > Adjust the logic so that policy is only applied when wakeup is
> > > > actually enabled.
> > > > 
> > > > Fixes: a5cfc9d65879c ("thunderbolt: Add wake on connect/disconnect on USB4 ports")
> > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> > > 
> > > Hi! There have been a couple of reports of a Thunderbolt regression in
> > > recent stable kernels, and one reporter has now bisected it to this
> > > change:
> > > 
> > >   • https://bugzilla.kernel.org/show_bug.cgi?id=220284
> > >   • https://github.com/NixOS/nixpkgs/issues/420730
> > > 
> > > Both reporters are CCed, and say it starts working after the module is
> > > reloaded.
> > > 
> > > Link: https://lore.kernel.org/r/bug-220284-208809@https.bugzilla.kernel.org%2F/
> > > (for regzbot)
> > 
> > Apparently[1] fixed by the first linked patch below, which is currently in
> > the Thunderbolt tree waiting to be pulled into the USB tree.
> > 
> > #regzbot monitor: https://lore.kernel.org/linux-usb/20250619213840.2388646-1-superm1@kernel.org/
> > #regzbot monitor: https://lore.kernel.org/linux-usb/20250626154009.GK2824380@black.fi.intel.com/
> > 
> > [1]: https://github.com/NixOS/nixpkgs/issues/420730#issuecomment-3018563631
> 
> Hey Greg,
> 
> Can you pick up the pull request from Mika from a week and a half ago with
> this fix for the next 6.16-rc?
> 
> https://lore.kernel.org/linux-usb/20250626154009.GK2824380@black.fi.intel.com/

Yes, I was waiting for this last round to go to Linus as the pull
request was made against a newer version of Linus's tree than I
currently had in my "for linus" branch.  I'll go get to that later
today.

thanks,

greg k-h