XPost: linux.debian.bugs.dist   
   From: post@ralfj.de   
      
   Hi all,   
      
   I did a (lengthy) bisect session, and came out with this commit:   
      
   52fbe173baa4df9d14bd733f42ee6b9ceab8299b is the first bad commit   
   commit 52fbe173baa4df9d14bd733f42ee6b9ceab8299b (HEAD)   
   Author: Ricardo Ribalda    
   Date:   Wed Dec 18 21:39:09 2024 +0000   
      
        media: uvcvideo: Invert default value for nodrop module param   
      
        The module param `nodrop` defines what to do with frames that contain an   
        error: drop them or sending them to userspace.   
      
        The default in the rest of the media subsystem is to return buffers with   
        an error to userspace with V4L2_BUF_FLAG_ERROR set in v4l2_buffer.flags.   
        In UVC we drop buffers with errors by default.   
      
        Change the default behaviour of uvcvideo to match the rest of the   
        drivers and maybe get rid of the module parameter in the future.   
      
        Suggested-by: Laurent Pinchart    
        Signed-off-by: Ricardo Ribalda    
        Reviewed-by: Laurent Pinchart    
        Reviewed-by: Hans de Goede    
        Link:   
   https://lore.kernel.org/r/20241218-uvc-deprecate-v2-2-ab814139e983@chromium.org   
        Signed-off-by: Laurent Pinchart    
        Signed-off-by: Mauro Carvalho Chehab    
      
     drivers/media/usb/uvc/uvc_driver.c | 2 +-   
     1 file changed, 1 insertion(+), 1 deletion(-)   
      
   I added Ricardo in Cc. Ricardo, see   
   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1121718 for context.   
      
   The bug does not always immediately manifest, so there is a small chance that   
   for some of the commits that I marked "good", artifacts would have started   
   appearing if I had waited a bit longer. But the commit seems reasonably   
   plausible to be able to cause the kind of error I am seeing.   
      
   Given that this is about a module parameter, I assume I could test this by   
   booting the latest kernel and setting the parameter back to its previous   
   value... but I don't know enough about how the kernel works to actually do   
   that.^^ Happy to try that if someone gives me some pointers.   
      
   Kind regards,   
   Ralf   
      
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