[PATCH] drm/arm/hdlcd: Simplify IRQ install/uninstall

[Liviu Dudau]

On Wed, Jun 15, 2022 at 05:11:09PM +0100, Robin Murphy wrote:
> Since we no longer need to conform to the structure of the various DRM
> IRQ callbacks, we can streamline the code by consolidating the piecemeal
> functions and passing around our private data structure directly. We're
> also a platform device so should never see IRQ_NOTCONNECTED either.
> 
> Furthermore we can also get rid of all the unnecesary read-modify-write
> operations, since on install we know we cleared the whole interrupt mask
> before enabling the debug IRQs, and thus on uninstall we're always
> clearing everything as well.
> 
> Signed-off-by: Robin Murphy <robin.murphy at arm.com>

Acked-by: Liviu Dudau <liviu.dudau at arm.com>

Thanks for the cleanup!

Best regards,
Liviu

> ---
>  drivers/gpu/drm/arm/hdlcd_drv.c | 62 +++++++++------------------------
>  1 file changed, 16 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
> index 1f1171f2f16a..7d6aa9b3b577 100644
> --- a/drivers/gpu/drm/arm/hdlcd_drv.c
> +++ b/drivers/gpu/drm/arm/hdlcd_drv.c
> @@ -41,8 +41,7 @@
>  
>  static irqreturn_t hdlcd_irq(int irq, void *arg)
>  {
> -	struct drm_device *drm = arg;
> -	struct hdlcd_drm_private *hdlcd = drm->dev_private;
> +	struct hdlcd_drm_private *hdlcd = arg;
>  	unsigned long irq_status;
>  
>  	irq_status = hdlcd_read(hdlcd, HDLCD_REG_INT_STATUS);
> @@ -70,61 +69,32 @@ static irqreturn_t hdlcd_irq(int irq, void *arg)
>  	return IRQ_HANDLED;
>  }
>  
> -static void hdlcd_irq_preinstall(struct drm_device *drm)
> -{
> -	struct hdlcd_drm_private *hdlcd = drm->dev_private;
> -	/* Ensure interrupts are disabled */
> -	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, 0);
> -	hdlcd_write(hdlcd, HDLCD_REG_INT_CLEAR, ~0);
> -}
> -
> -static void hdlcd_irq_postinstall(struct drm_device *drm)
> -{
> -#ifdef CONFIG_DEBUG_FS
> -	struct hdlcd_drm_private *hdlcd = drm->dev_private;
> -	unsigned long irq_mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
> -
> -	/* enable debug interrupts */
> -	irq_mask |= HDLCD_DEBUG_INT_MASK;
> -
> -	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, irq_mask);
> -#endif
> -}
> -
> -static int hdlcd_irq_install(struct drm_device *drm, int irq)
> +static int hdlcd_irq_install(struct hdlcd_drm_private *hdlcd)
>  {
>  	int ret;
>  
> -	if (irq == IRQ_NOTCONNECTED)
> -		return -ENOTCONN;
> +	/* Ensure interrupts are disabled */
> +	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, 0);
> +	hdlcd_write(hdlcd, HDLCD_REG_INT_CLEAR, ~0);
>  
> -	hdlcd_irq_preinstall(drm);
> -
> -	ret = request_irq(irq, hdlcd_irq, 0, drm->driver->name, drm);
> +	ret = request_irq(hdlcd->irq, hdlcd_irq, 0, "hdlcd", hdlcd);
>  	if (ret)
>  		return ret;
>  
> -	hdlcd_irq_postinstall(drm);
> +#ifdef CONFIG_DEBUG_FS
> +	/* enable debug interrupts */
> +	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, HDLCD_DEBUG_INT_MASK);
> +#endif
>  
>  	return 0;
>  }
>  
> -static void hdlcd_irq_uninstall(struct drm_device *drm)
> +static void hdlcd_irq_uninstall(struct hdlcd_drm_private *hdlcd)
>  {
> -	struct hdlcd_drm_private *hdlcd = drm->dev_private;
>  	/* disable all the interrupts that we might have enabled */
> -	unsigned long irq_mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
> +	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, 0);
>  
> -#ifdef CONFIG_DEBUG_FS
> -	/* disable debug interrupts */
> -	irq_mask &= ~HDLCD_DEBUG_INT_MASK;
> -#endif
> -
> -	/* disable vsync interrupts */
> -	irq_mask &= ~HDLCD_INTERRUPT_VSYNC;
> -	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, irq_mask);
> -
> -	free_irq(hdlcd->irq, drm);
> +	free_irq(hdlcd->irq, hdlcd);
>  }
>  
>  static int hdlcd_load(struct drm_device *drm, unsigned long flags)
> @@ -184,7 +154,7 @@ static int hdlcd_load(struct drm_device *drm, unsigned long flags)
>  		goto irq_fail;
>  	hdlcd->irq = ret;
>  
> -	ret = hdlcd_irq_install(drm, hdlcd->irq);
> +	ret = hdlcd_irq_install(hdlcd);
>  	if (ret < 0) {
>  		DRM_ERROR("failed to install IRQ handler\n");
>  		goto irq_fail;
> @@ -342,7 +312,7 @@ static int hdlcd_drm_bind(struct device *dev)
>  err_unload:
>  	of_node_put(hdlcd->crtc.port);
>  	hdlcd->crtc.port = NULL;
> -	hdlcd_irq_uninstall(drm);
> +	hdlcd_irq_uninstall(hdlcd);
>  	of_reserved_mem_device_release(drm->dev);
>  err_free:
>  	drm_mode_config_cleanup(drm);
> @@ -364,7 +334,7 @@ static void hdlcd_drm_unbind(struct device *dev)
>  	hdlcd->crtc.port = NULL;
>  	pm_runtime_get_sync(dev);
>  	drm_atomic_helper_shutdown(drm);
> -	hdlcd_irq_uninstall(drm);
> +	hdlcd_irq_uninstall(hdlcd);
>  	pm_runtime_put(dev);
>  	if (pm_runtime_enabled(dev))
>  		pm_runtime_disable(dev);
> -- 
> 2.36.1.dirty
> 

-- 
====================
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| but they're not |
| giving me the   |
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