Re: [PATCH v2] staging: fbtft: core: set smem_len before fb_deferred_io_init call - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Peter Suti <peter.suti@streamunlimited.com>
Cc: linux-fbdev@vger.kernel.org, linux-staging@lists.linux.dev,
	Javier Martinez Canillas <javierm@redhat.com>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Thomas Zimmermann <tzimmermann@suse.de>,
	chuansheng.liu@intel.com, dan.carpenter@oracle.com
Subject: Re: [PATCH v2] staging: fbtft: core: set smem_len before fb_deferred_io_init call
Date: Wed, 27 Jul 2022 09:13:00 +0200	[thread overview]
Message-ID: <YuDlfLeossnntH/C@kroah.com> (raw)
In-Reply-To: <20220727070723.1489599-1-peter.suti@streamunlimited.com>

On Wed, Jul 27, 2022 at 09:07:23AM +0200, Peter Suti wrote:
> 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.
> 
> Fixes: 856082f021a2 ("fbdev: defio: fix the pagelist corruption")
> 
> Signed-off-by: Peter Suti <peter.suti@streamunlimited.com>
> ---
>  drivers/staging/fbtft/fbtft-core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
> index 9b3eaed80cdd..afaba94d1d1c 100644
> --- a/drivers/staging/fbtft/fbtft-core.c
> +++ b/drivers/staging/fbtft/fbtft-core.c
> @@ -654,7 +654,6 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
>  	fbdefio->delay =            HZ / fps;
>  	fbdefio->sort_pagereflist = true;
>  	fbdefio->deferred_io =      fbtft_deferred_io;
> -	fb_deferred_io_init(info);
>  
>  	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
>  	info->fix.type =           FB_TYPE_PACKED_PIXELS;
> @@ -665,6 +664,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
>  	info->fix.line_length =    width * bpp / 8;
>  	info->fix.accel =          FB_ACCEL_NONE;
>  	info->fix.smem_len =       vmem_size;
> +	fb_deferred_io_init(info);
>  
>  	info->var.rotate =         pdata->rotate;
>  	info->var.xres =           width;
> -- 
> 2.25.1
> 
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for what needs to be done
  here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot