> Currently all drivers which use defio allocate system memory. All of them
> also set FBINFO_VIRTFB, other than ssd1307fb, however this driver allocates
> system RAM, so simply failed to set this flag when it ought to.
>
> This patch sets FBINFO_VIRTFB on ssd1307fb probe, then drops setting VM_IO
> in fb_deferred_io_mmap() and instead requires FBINFO_VIRTFB to be set,
> erroring out with a kernel warning if not.
>
> The logic requires a page from the driver and since commit 1ecbc7dd2902
> ("fbdev/deferred-io: Always call get_page() for framebuffer pages") has
> always required it to be refcounted, so this was implicitly already the
> case.
>
> Finally this patch sets VM_MIXEDMAP, as the logic is mapping
> kernel-allocated memory so this is appropriate.
>
> Reviewed-by: Thomas Zimmermann <[email protected]>
> Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review ยท
https://sashiko.dev/#/patchset/20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23...@kernel.org?part=19
