linux-kernel - Re: [PATCH] drm/arm: cleanup coding style in arm a bit

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Message-ID: <20200423125007.GG364558@e110455-lin.cambridge.arm.com>
Date:   Thu, 23 Apr 2020 13:50:07 +0100
From:   Liviu Dudau <liviu.dudau@....com>
To:     Bernard Zhao <bernard@...o.com>
Cc:     Brian Starkey <brian.starkey@....com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        opensource.kernel@...o.com
Subject: Re: [PATCH] drm/arm: cleanup coding style in arm a bit

Hi Bernard,

On Tue, Apr 21, 2020 at 07:10:46PM -0700, Bernard Zhao wrote:
> For the code logic, an alarm is thrown after failure, but the
> code continues to run and returns successfully, so to the caller
> the if check and return branch will never run.
> The change is to make the code a bit more readable.
> 
> Signed-off-by: Bernard Zhao <bernard@...o.com>
> ---
>  drivers/gpu/drm/arm/hdlcd_crtc.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c
> index af67fefed38d..32bda13250f5 100644
> --- a/drivers/gpu/drm/arm/hdlcd_crtc.c
> +++ b/drivers/gpu/drm/arm/hdlcd_crtc.c
> @@ -160,9 +160,7 @@ static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
>  	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
>  	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
>  
> -	err = hdlcd_set_pxl_fmt(crtc);
> -	if (err)
> -		return;
> +	hdlcd_set_pxl_fmt(crtc);

I think you found a real bug. hdlcd_set_pxl_fmt() is not supposed to return zero if
the format is not supported and here we would stop enabling the pixel clock.

Do you care to send a patch for fixing the bug, rather than this one?

Best regards,
Liviu

>  
>  	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
>  }
> -- 
> 2.26.2
> 

-- 
====================
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