Re: [PATCH] iio: buffer: Fix wait_queue not being removed

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Mon, Feb 23, 2026 at 01:39:37PM +0000, Nuno Sá wrote:
> On Sun, 2026-02-22 at 12:37 +0000, Jonathan Cameron wrote:
> > On Sat, 21 Feb 2026 15:27:42 -0600
> > David Lechner <dlechner@baylibre.com> wrote:
> > 
> > > On 2/16/26 7:24 AM, Nuno Sá via B4 Relay wrote:
> > > > From: Nuno Sá <nuno.sa@analog.com>
> > > > 
> > > > In the edge case where the IIO device is unregistered while we're
> > > > buffering, we were directly returning an error without removing the wait
> > > > queue. Instead, set 'ret' and break out of the loop.
> > > > 
> > > > Fixes: 9eeee3b0bf19 ("iio: Add output buffer support")
> > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > > ---  
> > > Reviewed-by: David Lechner <dlechner@baylibre.com>
> > > 
> > This brings the code inline with the near identical
> > flow in the read path.
> > 
> > It's been a while since I last looked at the locking / tear
> > down (what that ->info check is all about).  I'll add actually
> 
> Yeah not sure if you remember but I already said this a couple of times. In the buffer
> paths I'm not convinced the check we have is enough. Still very open to races AFAICT.
> I have it in my list to try and trigger and actual issue/dump on that path so it's not just
> theory. Already asked the bot to write some stressor/test code :).

Perhaps also a good task for stress-ng? Ask Colin!

> > documenting all the corner cases to the todo list as IIRC
> > there are some non obvious ordering constraints.  IIRC,
> > in the buffer paths, it is fairly straight forward
> > as it's just an optimization to avoid queuing or draining
> > data when the device is going down - nothing about the buffers
> > themselves involves interacting directly with the hardware.
> > 
> > Applied to the fixes-togreg branch of iio.git and marked
> > for stable.
> 
> BTW, I just realized we now have an Assisted-by: tag for getting help from AI. I should
> say that this bug was identified by Claude code (when bulding the stressor test app I 
> mentioned above :)). So, maybe (or can we Reported by: Claude Code?!!):

> Assisted-by: Claude Code

-- 
With Best Regards,
Andy Shevchenko