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

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

On Mon, Jul 14, 2025 at 11:35:39AM -0500, Mario Limonciello wrote:
> On 7/7/25 2:57 AM, Greg Kroah-Hartman wrote:
> > 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
> > 
> 
> Greg,
> 
> Sorry to be a bugger, but I was surprised I didn't see this come in -rc6
> this week, and I went and double checked your "usb-linus" branch [1] and
> didn't see it there.
> 
> Thanks,
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/log/?h=usb-linus

It's in there:

$ git lg main..usb-linus
*   cd0f8649d0e1 - (HEAD -> usb-linus, origin/usb-linus, kroah.org/usb-linus, work-linus) Merge tag 'usb-serial-6.16-rc6' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus (6 days ago) <Greg Kroah-Hartman>
|\  
| * 08f49cdb71f3 - USB: serial: option: add Foxconn T99W640 (3 weeks ago) <Slark Xiao>
* 3014168731b7 - usb: gadget: configfs: Fix OOB read on empty string write (6 days ago) <Xinyu Liu>
* 67a59f82196c - usb: musb: fix gadget state on disconnect (8 days ago) <Drew Hamilton>
* 9fccced2d25b - Merge tag 'thunderbolt-for-v6.16-rc4' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-linus (8 days ago) <Greg Kroah-Hartman>
* 2cdde91c14ec - thunderbolt: Fix bit masking in tb_dp_port_set_hops() (3 weeks ago) <Alok Tiwari>
* 58d71d4242ce - thunderbolt: Fix wake on connect at runtime (3 weeks ago) <Mario Limonciello>

I'll get this to Linus for the next -rc.

thanks,

greg k-h