linux-kernel - Re: [PATCH v2] video: fbdev: vesafb: add missed release

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Date:   Wed, 15 Jan 2020 15:50:16 +0100
From:   Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
To:     Chuhong Yuan <hslester96@...il.com>
Cc:     dri-devel@...ts.freedesktop.org, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] video: fbdev: vesafb: add missed release_region


On 12/5/19 5:07 PM, Chuhong Yuan wrote:
> The driver forgets to free the requested irq in remove and probe
> failure.

This is I/O region not IRQ.

> Add the missed calls to fix it.
> 
> Signed-off-by: Chuhong Yuan <hslester96@...il.com>
> ---
> Changes in v2:
>   - Modify commit message.
> 
>  drivers/video/fbdev/vesafb.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/video/fbdev/vesafb.c b/drivers/video/fbdev/vesafb.c
> index d9c08f6c2155..fbb196a8bbf6 100644
> --- a/drivers/video/fbdev/vesafb.c
> +++ b/drivers/video/fbdev/vesafb.c
> @@ -468,6 +468,7 @@ static int vesafb_probe(struct platform_device *dev)
>  	fb_info(info, "%s frame buffer device\n", info->fix.id);
>  	return 0;
>  err:
> +	release_region(0x3c0, 32);

There is one 'goto err;' instance before request_region() which
needs to be taken care of first.

>  	arch_phys_wc_del(par->wc_cookie);
>  	if (info->screen_base)
>  		iounmap(info->screen_base);
> @@ -480,6 +481,7 @@ static int vesafb_remove(struct platform_device *pdev)
>  {
>  	struct fb_info *info = platform_get_drvdata(pdev);
>  
> +	release_region(0x3c0, 32);
>  	unregister_framebuffer(info);

The order of operations on remove should be the reverse of
order of operations on probe.

[ We cannot release I/O region while framebuffer is active. ]

>  	framebuffer_release(info);

Please fix the patch and re-submit.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics