Hi Thomas,
On Tue, Jul 27, 2021 at 08:27:09PM +0200, Thomas Zimmermann wrote:
> Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
> IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
> don't benefit from using it.
>
> DRM IRQ callbacks are now being called directly or inlined.
>
> Calls to platform_get_irq() can fail with a negative errno code.
> Abort initialization in this case. The DRM IRQ midlayer does not
> handle this case correctly.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> drivers/gpu/drm/arm/hdlcd_drv.c | 174 ++++++++++++++++++--------------
> drivers/gpu/drm/arm/hdlcd_drv.h | 1 +
> 2 files changed, 97 insertions(+), 78 deletions(-)
>
> diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
> index 81ae92390736..b9998fe3982f 100644
> --- a/drivers/gpu/drm/arm/hdlcd_drv.c
> +++ b/drivers/gpu/drm/arm/hdlcd_drv.c
> @@ -29,7 +29,6 @@
> #include <drm/drm_fb_helper.h>
> #include <drm/drm_gem_cma_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_irq.h>
> #include <drm/drm_modeset_helper.h>
> #include <drm/drm_of.h>
> #include <drm/drm_probe_helper.h>
> @@ -38,6 +37,94 @@
> #include "hdlcd_drv.h"
> #include "hdlcd_regs.h"
>
> +static irqreturn_t hdlcd_irq(int irq, void *arg)
> +{
> + struct drm_device *drm = arg;
> + struct hdlcd_drm_private *hdlcd = drm->dev_private;
> + unsigned long irq_status;
> +
> + irq_status = hdlcd_read(hdlcd, HDLCD_REG_INT_STATUS);
> +
> +#ifdef CONFIG_DEBUG_FS
> + if (irq_status & HDLCD_INTERRUPT_UNDERRUN)
> + atomic_inc(&hdlcd->buffer_underrun_count);
> +
> + if (irq_status & HDLCD_INTERRUPT_DMA_END)
> + atomic_inc(&hdlcd->dma_end_count);
> +
> + if (irq_status & HDLCD_INTERRUPT_BUS_ERROR)
> + atomic_inc(&hdlcd->bus_error_count);
> +
> + if (irq_status & HDLCD_INTERRUPT_VSYNC)
> + atomic_inc(&hdlcd->vsync_count);
> +
> +#endif
> + if (irq_status & HDLCD_INTERRUPT_VSYNC)
> + drm_crtc_handle_vblank(&hdlcd->crtc);
> +
> + /* acknowledge interrupt(s) */
> + hdlcd_write(hdlcd, HDLCD_REG_INT_CLEAR, irq_status);
> +
> + 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 *dev, int irq)
It is inconsistent that the drm_device * is named "dev", as similar
functions in this patch uses the name "drm".
> +{
> + int ret;
> +
> + if (irq == IRQ_NOTCONNECTED)
> + return -ENOTCONN;
The code above is almost redundandt as request_irq has the same check.
The only benefit of this check is that we avoid calling
hdlcd_irq_preinstall().
And IRQ_NOTCONNECTED is only set for PCI devices which this is not.
So I would thing the if () should be dropped here. ??
With the inputs considered/addressed:
Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> +
> + hdlcd_irq_preinstall(dev);
> +
> + ret = request_irq(irq, hdlcd_irq, 0, dev->driver->name, dev);
> + if (ret)
> + return ret;
> +
> + hdlcd_irq_postinstall(dev);
> +
> + return 0;
> +}
> +
> +static void hdlcd_irq_uninstall(struct drm_device *drm)
> +{
> + 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);
> +
> +#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);
> +}
> +
> static int hdlcd_load(struct drm_device *drm, unsigned long flags)
> {
> struct hdlcd_drm_private *hdlcd = drm->dev_private;
> @@ -90,7 +177,12 @@ static int hdlcd_load(struct drm_device *drm, unsigned long flags)
> goto setup_fail;
> }
>
> - ret = drm_irq_install(drm, platform_get_irq(pdev, 0));
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + goto irq_fail;
> + hdlcd->irq = ret;
> +
> + ret = hdlcd_irq_install(drm, hdlcd->irq);
> if (ret < 0) {
> DRM_ERROR("failed to install IRQ handler\n");
> goto irq_fail;
> @@ -122,76 +214,6 @@ static void hdlcd_setup_mode_config(struct drm_device *drm)
> drm->mode_config.funcs = &hdlcd_mode_config_funcs;
> }
>
> -static irqreturn_t hdlcd_irq(int irq, void *arg)
> -{
> - struct drm_device *drm = arg;
> - struct hdlcd_drm_private *hdlcd = drm->dev_private;
> - unsigned long irq_status;
> -
> - irq_status = hdlcd_read(hdlcd, HDLCD_REG_INT_STATUS);
> -
> -#ifdef CONFIG_DEBUG_FS
> - if (irq_status & HDLCD_INTERRUPT_UNDERRUN)
> - atomic_inc(&hdlcd->buffer_underrun_count);
> -
> - if (irq_status & HDLCD_INTERRUPT_DMA_END)
> - atomic_inc(&hdlcd->dma_end_count);
> -
> - if (irq_status & HDLCD_INTERRUPT_BUS_ERROR)
> - atomic_inc(&hdlcd->bus_error_count);
> -
> - if (irq_status & HDLCD_INTERRUPT_VSYNC)
> - atomic_inc(&hdlcd->vsync_count);
> -
> -#endif
> - if (irq_status & HDLCD_INTERRUPT_VSYNC)
> - drm_crtc_handle_vblank(&hdlcd->crtc);
> -
> - /* acknowledge interrupt(s) */
> - hdlcd_write(hdlcd, HDLCD_REG_INT_CLEAR, irq_status);
> -
> - 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 int 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
> - return 0;
> -}
> -
> -static void hdlcd_irq_uninstall(struct drm_device *drm)
> -{
> - 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);
> -
> -#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);
> -}
> -
> #ifdef CONFIG_DEBUG_FS
> static int hdlcd_show_underrun_count(struct seq_file *m, void *arg)
> {
> @@ -236,10 +258,6 @@ DEFINE_DRM_GEM_CMA_FOPS(fops);
>
> static const struct drm_driver hdlcd_driver = {
> .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> - .irq_handler = hdlcd_irq,
> - .irq_preinstall = hdlcd_irq_preinstall,
> - .irq_postinstall = hdlcd_irq_postinstall,
> - .irq_uninstall = hdlcd_irq_uninstall,
> DRM_GEM_CMA_DRIVER_OPS,
> #ifdef CONFIG_DEBUG_FS
> .debugfs_init = hdlcd_debugfs_init,
> @@ -316,7 +334,7 @@ static int hdlcd_drm_bind(struct device *dev)
> err_unload:
> of_node_put(hdlcd->crtc.port);
> hdlcd->crtc.port = NULL;
> - drm_irq_uninstall(drm);
> + hdlcd_irq_uninstall(drm);
> of_reserved_mem_device_release(drm->dev);
> err_free:
> drm_mode_config_cleanup(drm);
> @@ -338,7 +356,7 @@ static void hdlcd_drm_unbind(struct device *dev)
> hdlcd->crtc.port = NULL;
> pm_runtime_get_sync(dev);
> drm_atomic_helper_shutdown(drm);
> - drm_irq_uninstall(drm);
> + hdlcd_irq_uninstall(drm);
> pm_runtime_put(dev);
> if (pm_runtime_enabled(dev))
> pm_runtime_disable(dev);
> diff --git a/drivers/gpu/drm/arm/hdlcd_drv.h b/drivers/gpu/drm/arm/hdlcd_drv.h
> index fd438d177b64..909c39c28487 100644
> --- a/drivers/gpu/drm/arm/hdlcd_drv.h
> +++ b/drivers/gpu/drm/arm/hdlcd_drv.h
> @@ -11,6 +11,7 @@ struct hdlcd_drm_private {
> struct clk *clk;
> struct drm_crtc crtc;
> struct drm_plane *plane;
> + unsigned int irq;
> #ifdef CONFIG_DEBUG_FS
> atomic_t buffer_underrun_count;
> atomic_t bus_error_count;
> --
> 2.32.0
