On 3/3/22 21:58, Thomas Zimmermann wrote: > The fbdev mmap function fb_mmap() unconditionally overrides the > driver's implementation if deferred I/O has been activated. This > makes it hard to implement mmap with anything but a vmalloc()'ed > software buffer. That is specifically a problem for DRM, where > video memory is maintained by a memory manager. > > Leave the mmap handling to drivers and expect them to call the > helper for deferred I/O by thmeselves. > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > --- [snip] > > + /* > + * FB deferred I/O want you to handle mmap in your drivers. At a > + * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap(). > + */ > + if (WARN_ON_ONCE(info->fbdefio)) > + return -ENODEV; > + Maybe part of that comment could be printed as a WARN_ON_ONCE() message ? Regardless, the patch looks good to me: Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> -- Best regards, Javier Martinez Canillas Linux Engineering Red Hat
