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

[Geert Uytterhoeven <geert@linux-m68k.org>]

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