[PATCH v3] staging: fbtft: core: set smem_len before fb_deferred_io_init call

[Liu, Chuansheng]

Hi Peter,

> -----Original Message-----
> From: Peter Suti <peter.suti at streamunlimited.com>
> Sent: Wednesday, July 27, 2022 3:36 PM
> To: Liu, Chuansheng <chuansheng.liu at intel.com>; dan.carpenter at oracle.com;
> Greg Kroah-Hartman <gregkh at linuxfoundation.org>; Thomas Zimmermann
> <tzimmermann at suse.de>; Javier Martinez Canillas <javierm at redhat.com>
> Cc: Peter Suti <peter.suti at streamunlimited.com>; dri-
> devel at lists.freedesktop.org; linux-fbdev at vger.kernel.org; linux-
> staging at lists.linux.dev; linux-kernel at vger.kernel.org
> Subject: [PATCH v3] staging: fbtft: core: set smem_len before
> fb_deferred_io_init call
> 
> 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().

> 
> Fixes: 856082f021a2 ("fbdev: defio: fix the pagelist corruption")

Don't agree with such description.

Best Regards
Chuansheng