Hi Thomas,
On Tue, Aug 03, 2021 at 11:07:01AM +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.
I cannot see why the irq_enabled flag is needed here, and the changelog
do not help me.
What do I miss?
Sam
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> drivers/gpu/drm/tilcdc/tilcdc_drv.c | 51 ++++++++++++++++++++++-------
> drivers/gpu/drm/tilcdc/tilcdc_drv.h | 3 ++
> 2 files changed, 43 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> index f1d3a9f919fd..6b03f89a98d4 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> @@ -20,7 +20,6 @@
> #include <drm/drm_fourcc.h>
> #include <drm/drm_gem_cma_helper.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_irq.h>
> #include <drm/drm_mm.h>
> #include <drm/drm_probe_helper.h>
> #include <drm/drm_vblank.h>
> @@ -124,6 +123,39 @@ static int cpufreq_transition(struct notifier_block *nb,
> }
> #endif
>
> +static irqreturn_t tilcdc_irq(int irq, void *arg)
> +{
> + struct drm_device *dev = arg;
> + struct tilcdc_drm_private *priv = dev->dev_private;
> +
> + return tilcdc_crtc_irq(priv->crtc);
> +}
> +
> +static int tilcdc_irq_install(struct drm_device *dev, unsigned int irq)
> +{
> + struct tilcdc_drm_private *priv = dev->dev_private;
> + int ret;
> +
> + ret = request_irq(irq, tilcdc_irq, 0, dev->driver->name, dev);
> + if (ret)
> + return ret;
> +
> + priv->irq_enabled = false;
> +
> + return 0;
> +}
> +
> +static void tilcdc_irq_uninstall(struct drm_device *dev)
> +{
> + struct tilcdc_drm_private *priv = dev->dev_private;
> +
> + if (!priv->irq_enabled)
> + return;
> +
> + free_irq(priv->irq, dev);
> + priv->irq_enabled = false;
> +}
> +
> /*
> * DRM operations:
> */
> @@ -145,7 +177,7 @@ static void tilcdc_fini(struct drm_device *dev)
> drm_dev_unregister(dev);
>
> drm_kms_helper_poll_fini(dev);
> - drm_irq_uninstall(dev);
> + tilcdc_irq_uninstall(dev);
> drm_mode_config_cleanup(dev);
>
> if (priv->clk)
> @@ -336,7 +368,12 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
> goto init_failed;
> }
>
> - ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + goto init_failed;
> + priv->irq = ret;
> +
> + ret = tilcdc_irq_install(ddev, priv->irq);
> if (ret < 0) {
> dev_err(dev, "failed to install IRQ handler\n");
> goto init_failed;
> @@ -360,13 +397,6 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
> return ret;
> }
>
> -static irqreturn_t tilcdc_irq(int irq, void *arg)
> -{
> - struct drm_device *dev = arg;
> - struct tilcdc_drm_private *priv = dev->dev_private;
> - return tilcdc_crtc_irq(priv->crtc);
> -}
> -
> #if defined(CONFIG_DEBUG_FS)
> static const struct {
> const char *name;
> @@ -454,7 +484,6 @@ DEFINE_DRM_GEM_CMA_FOPS(fops);
>
> static const struct drm_driver tilcdc_driver = {
> .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> - .irq_handler = tilcdc_irq,
> DRM_GEM_CMA_DRIVER_OPS,
> #ifdef CONFIG_DEBUG_FS
> .debugfs_init = tilcdc_debugfs_init,
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
> index d29806ca8817..b818448c83f6 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
> @@ -46,6 +46,8 @@ struct tilcdc_drm_private {
> struct clk *clk; /* functional clock */
> int rev; /* IP revision */
>
> + unsigned int irq;
> +
> /* don't attempt resolutions w/ higher W * H * Hz: */
> uint32_t max_bandwidth;
> /*
> @@ -82,6 +84,7 @@ struct tilcdc_drm_private {
>
> bool is_registered;
> bool is_componentized;
> + bool irq_enabled;
> };
>
> /* Sub-module for display. Since we don't know at compile time what panels
> --
> 2.32.0
