[PATCH v2] drm/rockchip: Don't continue trying to enable crtc on failure

[Yakir Yang]

Sean,

On 08/16/2016 07:12 AM, Sean Paul wrote:
> If vop_enable fails, don't continue on, it causes system hangs.
>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>

Also meet this problem on my Rk3399 Kevin board. VOP just failed to get 
the pm_runtime at resume time, but ｄｒｉｖer still just continue without 
anything enable rightly, oops, and then system crashed :(

So this patch looks good to me, and also fix my problem, thanks:

Ｒｅviewed-by: Yakir Yang <ykk at rock-chips.com>
Tested-by: Yakir Yang <ykk at rock-chips.com>

Thanks,
- Yakir
> ---
>
> This patch uses the new DRM_DEV_ERROR logging, so it should be applied on
> top of "[PATCH 2/2] drm/rockchip: Use DRM_DEV_ERROR in vop".
>
> Changes in v2:
> 	- Escalate dev_err to WARN_ON for clk_enable failures (Daniel Vetter)
>
> Sean
>
>
>   drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 31 ++++++++++++++++-------------
>   1 file changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index ec8ad00..a176d03 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -428,7 +428,7 @@ static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
>   	spin_unlock_irqrestore(&vop->irq_lock, flags);
>   }
>   
> -static void vop_enable(struct drm_crtc *crtc)
> +static int vop_enable(struct drm_crtc *crtc)
>   {
>   	struct vop *vop = to_vop(crtc);
>   	int ret;
> @@ -436,26 +436,20 @@ static void vop_enable(struct drm_crtc *crtc)
>   	ret = pm_runtime_get_sync(vop->dev);
>   	if (ret < 0) {
>   		dev_err(vop->dev, "failed to get pm runtime: %d\n", ret);
> -		return;
> +		goto err_put_pm_runtime;
>   	}
>   
>   	ret = clk_enable(vop->hclk);
> -	if (ret < 0) {
> -		dev_err(vop->dev, "failed to enable hclk - %d\n", ret);
> -		return;
> -	}
> +	if (WARN_ON(ret < 0))
> +		goto err_put_pm_runtime;
>   
>   	ret = clk_enable(vop->dclk);
> -	if (ret < 0) {
> -		dev_err(vop->dev, "failed to enable dclk - %d\n", ret);
> +	if (WARN_ON(ret < 0))
>   		goto err_disable_hclk;
> -	}
>   
>   	ret = clk_enable(vop->aclk);
> -	if (ret < 0) {
> -		dev_err(vop->dev, "failed to enable aclk - %d\n", ret);
> +	if (WARN_ON(ret < 0))
>   		goto err_disable_dclk;
> -	}
>   
>   	/*
>   	 * Slave iommu shares power, irq and clock with vop.  It was associated
> @@ -485,7 +479,7 @@ static void vop_enable(struct drm_crtc *crtc)
>   
>   	drm_crtc_vblank_on(crtc);
>   
> -	return;
> +	return 0;
>   
>   err_disable_aclk:
>   	clk_disable(vop->aclk);
> @@ -493,6 +487,9 @@ err_disable_dclk:
>   	clk_disable(vop->dclk);
>   err_disable_hclk:
>   	clk_disable(vop->hclk);
> +err_put_pm_runtime:
> +	pm_runtime_put_sync(vop->dev);
> +	return ret;
>   }
>   
>   static void vop_crtc_disable(struct drm_crtc *crtc)
> @@ -912,10 +909,16 @@ static void vop_crtc_enable(struct drm_crtc *crtc)
>   	u16 vact_st = adjusted_mode->vtotal - adjusted_mode->vsync_start;
>   	u16 vact_end = vact_st + vdisplay;
>   	uint32_t val;
> +	int ret;
>   
>   	WARN_ON(vop->event);
>   
> -	vop_enable(crtc);
> +	ret = vop_enable(crtc);
> +	if (ret) {
> +		DRM_DEV_ERROR(vop->dev, "Failed to enable vop (%d)\n", ret);
> +		return;
> +	}
> +
>   	/*
>   	 * If dclk rate is zero, mean that scanout is stop,
>   	 * we don't need wait any more.