On Thu, Jul 28, 2022 at 12:49:15PM +0000, Liu, Chuansheng wrote:
> Hi Peter,
>
> >
> > The fbtft_framebuffer_alloc() calls fb_deferred_io_init() before
> > initializing info->fix.smem_len. It is set to zero by the
> > framebuffer_alloc() function. It will trigger a WARN_ON() at the
> > start of fb_deferred_io_init() and the function will not do anything.
>
> Please show us the WARN_ON() call stack, then everything is clear.
> It is the driver itself issue to be fixed. I saw Thomas made such
> WARN_ON().
I don't understand the confusion here. The code is very simple and the
description seems very clear. No need to redo the patch. I think
Peter tested it before the WARN_ON() was added so he probably didn't
see the WARN_ON(). I told him to add that because it's pretty obvious
what will happen just from reading the code.
>
> >
> > Fixes: 856082f021a2 ("fbdev: defio: fix the pagelist corruption")
>
> Don't agree with such description.
I don't see how you can disagree? Before your patch the
fb_deferred_io_init() did not use info->fix.smem_len and now it does.
regards,
dan carpenter
