linux-kernel - Re: [PATCH] drm/i915/gvt: Use common error handling code in shadow_workload_ring

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Message-ID: <87efpsiu7r.fsf@intel.com>
Date:   Tue, 24 Oct 2017 15:52:24 +0300
From:   Jani Nikula <jani.nikula@...ux.intel.com>
To:     SF Markus Elfring <elfring@...rs.sourceforge.net>,
        dri-devel@...ts.freedesktop.org, intel-gfx@...ts.freedesktop.org,
        intel-gvt-dev@...ts.freedesktop.org,
        David Airlie <airlied@...ux.ie>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Zhi Wang <zhi.a.wang@...el.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] drm/i915/gvt: Use common error handling code in shadow_workload_ring_buffer()

On Tue, 24 Oct 2017, SF Markus Elfring <elfring@...rs.sourceforge.net> wrote:
> From: Markus Elfring <elfring@...rs.sourceforge.net>
> Date: Tue, 24 Oct 2017 14:20:06 +0200
>
> Add a jump target so that a call of the function "gvt_vgpu_err" is stored
> only once at the end of this function implementation.
> Replace two calls by goto statements.
>
> This issue was detected by using the Coccinelle software.

I don't think this is an issue or an improvement.

BR,
Jani.

>
> Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
> ---
>  drivers/gpu/drm/i915/gvt/cmd_parser.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> index 2c0ccbb817dc..caa181380958 100644
> --- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
> +++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> @@ -2640,10 +2640,9 @@ static int shadow_workload_ring_buffer(struct intel_vgpu_workload *workload)
>  	if (gma_head > gma_tail) {
>  		ret = copy_gma_to_hva(vgpu, vgpu->gtt.ggtt_mm,
>  				      gma_head, gma_top, shadow_ring_buffer_va);
> -		if (ret < 0) {
> -			gvt_vgpu_err("fail to copy guest ring buffer\n");
> -			return ret;
> -		}
> +		if (ret < 0)
> +			goto report_failure;
> +
>  		shadow_ring_buffer_va += ret;
>  		gma_head = workload->rb_start;
>  	}
> @@ -2651,11 +2650,14 @@ static int shadow_workload_ring_buffer(struct intel_vgpu_workload *workload)
>  	/* copy head or start <-> tail */
>  	ret = copy_gma_to_hva(vgpu, vgpu->gtt.ggtt_mm, gma_head, gma_tail,
>  				shadow_ring_buffer_va);
> -	if (ret < 0) {
> -		gvt_vgpu_err("fail to copy guest ring buffer\n");
> -		return ret;
> -	}
> +	if (ret < 0)
> +		goto report_failure;
> +
>  	return 0;
> +
> +report_failure:
> +	gvt_vgpu_err("fail to copy guest ring buffer\n");
> +	return ret;
>  }
>  
>  int intel_gvt_scan_and_shadow_ringbuffer(struct intel_vgpu_workload *workload)

-- 
Jani Nikula, Intel Open Source Technology Center