Re: [PATCH] drm/xlnx: Use devm_drm_dev_alloc

From: Hyun Kwon <hyun.kwon@xilinx.com>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
	DRI Development <dri-devel@lists.freedesktop.org>,
	Michal Simek <michals@xilinx.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Daniel Vetter <daniel.vetter@intel.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] drm/xlnx: Use devm_drm_dev_alloc
Date: Tue, 8 Sep 2020 12:16:00 -0700	[thread overview]
Message-ID: <20200908191600.GA1569998@xilinx.com> (raw)
In-Reply-To: <20200907082225.150837-1-daniel.vetter@ffwll.ch>

Hi Daniel,

On Mon, Sep 07, 2020 at 01:22:25AM -0700, Daniel Vetter wrote:
> Gets rid of drmm_add_final_kfree, which I want to unexport so that it
> stops confusion people about this transitional state of rolling drm
> managed memory out.
> 
> This also fixes the missing drm_dev_put in the error path of the probe
> code.
> 
> v2: Drop the misplaced drm_dev_put from zynqmp_dpsub_drm_init (all
> other paths leaked on error, this should have been in
> zynqmp_dpsub_probe), now that subsumed by the auto-cleanup of
> devm_drm_dev_alloc.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Hyun Kwon <hyun.kwon@xilinx.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: linux-arm-kernel@lists.infradead.org

Looks correct to me.

Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>

Thanks!

-hyun

> ---
>  drivers/gpu/drm/xlnx/zynqmp_dpsub.c | 27 ++++++---------------------
>  1 file changed, 6 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
> index 26328c76305b..8e69303aad3f 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c
> @@ -111,7 +111,7 @@ static int zynqmp_dpsub_drm_init(struct zynqmp_dpsub *dpsub)
>  	/* Initialize mode config, vblank and the KMS poll helper. */
>  	ret = drmm_mode_config_init(drm);
>  	if (ret < 0)
> -		goto err_dev_put;
> +		return ret;
>  
>  	drm->mode_config.funcs = &zynqmp_dpsub_mode_config_funcs;
>  	drm->mode_config.min_width = 0;
> @@ -121,7 +121,7 @@ static int zynqmp_dpsub_drm_init(struct zynqmp_dpsub *dpsub)
>  
>  	ret = drm_vblank_init(drm, 1);
>  	if (ret)
> -		goto err_dev_put;
> +		return ret;
>  
>  	drm->irq_enabled = 1;
>  
> @@ -154,8 +154,6 @@ static int zynqmp_dpsub_drm_init(struct zynqmp_dpsub *dpsub)
>  
>  err_poll_fini:
>  	drm_kms_helper_poll_fini(drm);
> -err_dev_put:
> -	drm_dev_put(drm);
>  	return ret;
>  }
>  
> @@ -208,27 +206,16 @@ static int zynqmp_dpsub_probe(struct platform_device *pdev)
>  	int ret;
>  
>  	/* Allocate private data. */
> -	dpsub = kzalloc(sizeof(*dpsub), GFP_KERNEL);
> -	if (!dpsub)
> -		return -ENOMEM;
> +	dpsub = devm_drm_dev_alloc(&pdev->dev, &zynqmp_dpsub_drm_driver,
> +				   struct zynqmp_dpsub, drm);
> +	if (IS_ERR(dpsub))
> +		return PTR_ERR(dpsub);
>  
>  	dpsub->dev = &pdev->dev;
>  	platform_set_drvdata(pdev, dpsub);
>  
>  	dma_set_mask(dpsub->dev, DMA_BIT_MASK(ZYNQMP_DISP_MAX_DMA_BIT));
>  
> -	/*
> -	 * Initialize the DRM device early, as the DRM core mandates usage of
> -	 * the managed memory helpers tied to the DRM device.
> -	 */
> -	ret = drm_dev_init(&dpsub->drm, &zynqmp_dpsub_drm_driver, &pdev->dev);
> -	if (ret < 0) {
> -		kfree(dpsub);
> -		return ret;
> -	}
> -
> -	drmm_add_final_kfree(&dpsub->drm, dpsub);
> -
>  	/* Try the reserved memory. Proceed if there's none. */
>  	of_reserved_mem_device_init(&pdev->dev);
>  
> @@ -286,8 +273,6 @@ static int zynqmp_dpsub_remove(struct platform_device *pdev)
>  	clk_disable_unprepare(dpsub->apb_clk);
>  	of_reserved_mem_device_release(&pdev->dev);
>  
> -	drm_dev_put(drm);
> -
>  	return 0;
>  }
>  
> -- 
> 2.28.0
> 

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