[PATCH] drm/shmobile: Convert to Linux IRQ interfaces

[PATCH] drm/shmobile: Convert to Linux IRQ interfaces

[Thomas Zimmermann]

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.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/shmobile/shmob_drm_drv.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/shmobile/shmob_drm_drv.c b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
index 0a02b7092c04..032a2fff5efd 100644
--- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
+++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
@@ -18,7 +18,6 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_gem_cma_helper.h>
-#include <drm/drm_irq.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -130,7 +129,6 @@ DEFINE_DRM_GEM_CMA_FOPS(shmob_drm_fops);
 
 static const struct drm_driver shmob_drm_driver = {
 	.driver_features	= DRIVER_GEM | DRIVER_MODESET,
-	.irq_handler		= shmob_drm_irq,
 	DRM_GEM_CMA_DRIVER_OPS,
 	.fops			= &shmob_drm_fops,
 	.name			= "shmob-drm",
@@ -183,7 +181,7 @@ static int shmob_drm_remove(struct platform_device *pdev)
 
 	drm_dev_unregister(ddev);
 	drm_kms_helper_poll_fini(ddev);
-	drm_irq_uninstall(ddev);
+	free_irq(platform_get_irq(pdev, 0), ddev);
 	drm_dev_put(ddev);
 
 	return 0;
@@ -258,7 +256,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
 		goto err_modeset_cleanup;
 	}
 
-	ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
+	ret = request_irq(platform_get_irq(pdev, 0), shmob_drm_irq, 0, ddev->driver->name, ddev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to install IRQ handler\n");
 		goto err_modeset_cleanup;
@@ -275,7 +273,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
 	return 0;
 
 err_irq_uninstall:
-	drm_irq_uninstall(ddev);
+	free_irq(platform_get_irq(pdev, 0), ddev);
 err_modeset_cleanup:
 	drm_kms_helper_poll_fini(ddev);
 err_free_drm_dev:
-- 
2.32.0

Re: [PATCH] drm/shmobile: Convert to Linux IRQ interfaces

[Laurent Pinchart]

Hi Thomas,

Thank you for the patch.

On Tue, Jul 06, 2021 at 09:49:00AM +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.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/shmobile/shmob_drm_drv.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/shmobile/shmob_drm_drv.c b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> index 0a02b7092c04..032a2fff5efd 100644
> --- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> +++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> @@ -18,7 +18,6 @@
>  #include <drm/drm_crtc_helper.h>
>  #include <drm/drm_drv.h>
>  #include <drm/drm_gem_cma_helper.h>
> -#include <drm/drm_irq.h>
>  #include <drm/drm_probe_helper.h>
>  #include <drm/drm_vblank.h>
>  
> @@ -130,7 +129,6 @@ DEFINE_DRM_GEM_CMA_FOPS(shmob_drm_fops);
>  
>  static const struct drm_driver shmob_drm_driver = {
>  	.driver_features	= DRIVER_GEM | DRIVER_MODESET,
> -	.irq_handler		= shmob_drm_irq,
>  	DRM_GEM_CMA_DRIVER_OPS,
>  	.fops			= &shmob_drm_fops,
>  	.name			= "shmob-drm",
> @@ -183,7 +181,7 @@ static int shmob_drm_remove(struct platform_device *pdev)
>  
>  	drm_dev_unregister(ddev);
>  	drm_kms_helper_poll_fini(ddev);
> -	drm_irq_uninstall(ddev);
> +	free_irq(platform_get_irq(pdev, 0), ddev);
>  	drm_dev_put(ddev);
>  
>  	return 0;
> @@ -258,7 +256,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
>  		goto err_modeset_cleanup;
>  	}
>  
> -	ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
> +	ret = request_irq(platform_get_irq(pdev, 0), shmob_drm_irq, 0, ddev->driver->name, ddev);

Could you store the irq number in a local variable, and wrap this line
at 80 columns ? You can then use the local variable in the free_irq()
call below. With this addressed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>  	if (ret < 0) {
>  		dev_err(&pdev->dev, "failed to install IRQ handler\n");
>  		goto err_modeset_cleanup;
> @@ -275,7 +273,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_irq_uninstall:
> -	drm_irq_uninstall(ddev);
> +	free_irq(platform_get_irq(pdev, 0), ddev);
>  err_modeset_cleanup:
>  	drm_kms_helper_poll_fini(ddev);
>  err_free_drm_dev:

-- 
Regards,

Laurent Pinchart

Re: [PATCH] drm/shmobile: Convert to Linux IRQ interfaces

[Geert Uytterhoeven]

Hi Thomas,

On Tue, Jul 6, 2021 at 9:49 AM Thomas Zimmermann <tzimmermann@suse.de> 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.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Thanks for your patch!

> --- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> +++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> @@ -258,7 +256,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
>                 goto err_modeset_cleanup;
>         }
>
> -       ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
> +       ret = request_irq(platform_get_irq(pdev, 0), shmob_drm_irq, 0, ddev->driver->name, ddev);

platform_get_irq() can return a negative error code.
While drm_irq_install() took a signed irq parameter (and only
considered zero an error, oops), request_irq() takes an unsigned irq.
So you better check for errors before calling request_irq().

>         if (ret < 0) {
>                 dev_err(&pdev->dev, "failed to install IRQ handler\n");
>                 goto err_modeset_cleanup;
> @@ -275,7 +273,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
>         return 0;
>
>  err_irq_uninstall:
> -       drm_irq_uninstall(ddev);
> +       free_irq(platform_get_irq(pdev, 0), ddev);

Similar issue here.

>  err_modeset_cleanup:
>         drm_kms_helper_poll_fini(ddev);
>  err_free_drm_dev:

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] drm/shmobile: Convert to Linux IRQ interfaces

[Sergei Shtylyov]

On 7/6/21 10:49 AM, 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.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/shmobile/shmob_drm_drv.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/shmobile/shmob_drm_drv.c b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> index 0a02b7092c04..032a2fff5efd 100644
> --- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
> +++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
[...]
> @@ -258,7 +256,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
>  		goto err_modeset_cleanup;
>  	}
>  
> -	ret = drm_irq_install(ddev, platform_get_irq(pdev, 0));
> +	ret = request_irq(platform_get_irq(pdev, 0), shmob_drm_irq, 0, ddev->driver->name, ddev);

   You can't call request_irq() on the result of platfrom_get_irq(), you need to check ifq >= 0 first!
You really need a local (or even global) variable for the IRQ #...

[...]

MBR, Sergei