Re: [PATCH] [drivers] [fb] S3C-fb: PM fix

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 18 May 2009 08:05:46 +0200 Marek Szyprowski <m.szyprowski@samsung.com> wrote:

> Restore correctly FrameBuffer registers state in resume function.
> 
> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> 
> --- 
> 
> diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
> index 5e9c630..d3a568e 100644
> --- a/drivers/video/s3c-fb.c
> +++ b/drivers/video/s3c-fb.c
> @@ -947,7 +947,8 @@ static int __devexit s3c_fb_remove(struct platform_device *pdev)
>  	int win;
>  
>  	for (win = 0; win <= S3C_FB_MAX_WIN; win++)
> -		s3c_fb_release_win(sfb, sfb->windows[win]);
> +		if (sfb->windows[win])
> +			s3c_fb_release_win(sfb, sfb->windows[win]);
>  
>  	iounmap(sfb->regs);
>  
> @@ -985,11 +986,20 @@ static int s3c_fb_suspend(struct platform_device *pdev, pm_message_t state)
>  static int s3c_fb_resume(struct platform_device *pdev)
>  {
>  	struct s3c_fb *sfb = platform_get_drvdata(pdev);
> +	struct s3c_fb_platdata *pd = sfb->pdata;
>  	struct s3c_fb_win *win;
>  	int win_no;
>  
>  	clk_enable(sfb->bus_clk);
>  
> +	/* setup registers */
> +	writel(pd->vidcon1, sfb->regs + VIDCON1);
> +
> +	/* zero all windows before we do anything */
> +	for (win_no = 0; win_no < S3C_FB_MAX_WIN; win_no++)
> +		s3c_fb_clear_win(sfb, win_no);
> +
> +	/* restore framebuffers */
>  	for (win_no = 0; win_no < S3C_FB_MAX_WIN; win_no++) {
>  		win = sfb->windows[win_no];
>  		if (!win)

What are the consequences of the bug whcih you fixed?  Device
inoperative after resume, I assume?  Does it affect all supported
hardware, or just some particualr device(s)?

See, this is the sort of information whcih shuld be in the changelog,
please, so I (and others) can make decisions about which kernel
version(s) the patch should be merged into.

I assume we want it in 2.6.30.

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