Re: [PATCH 2/5] drm/exynos: mixer: Use platform_get_irq() to get the interrupt

From: Inki Dae
Date: Fri Jan 14 2022 - 06:08:41 EST


Hi Lad Prabhakar,

21. 12. 23. 오전 4:01에 Lad Prabhakar 이(가) 쓴 글:
> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> allocation of IRQ resources in DT core code, this causes an issue
> when using hierarchical interrupt domains using "interrupts" property
> in the node as this bypassed the hierarchical setup and messed up the
> irq chaining.
>
> In preparation for removal of static setup of IRQ resource from DT core
> code use platform_get_irq().
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> Hi,
>
> Ideally I would expect the mixer_resources_init() to be called from probe
> instead from the bind callback. If platform_get_irq() returns -EPROBE_DEFER
> the bind callback will fail :(

If the bind callback failed then probe function of exynos drm driver will call -EPROBE_DEFER like below so it must be no problem :),
--------------------------------------------
in exynos_drm_platform_probe function
component_master_add_with_match()

in component_master_add_with_match function
try_to_bring_up_master()

Thanks,
Inki Dae

>
> Cheers,
> Prabhakar
> ---
> drivers/gpu/drm/exynos/exynos_mixer.c | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
> index 41c54f1f60bc..e5204be86093 100644
> --- a/drivers/gpu/drm/exynos/exynos_mixer.c
> +++ b/drivers/gpu/drm/exynos/exynos_mixer.c
> @@ -809,19 +809,17 @@ static int mixer_resources_init(struct mixer_context *mixer_ctx)
> return -ENXIO;
> }
>
> - res = platform_get_resource(mixer_ctx->pdev, IORESOURCE_IRQ, 0);
> - if (res == NULL) {
> - dev_err(dev, "get interrupt resource failed.\n");
> - return -ENXIO;
> - }
> + ret = platform_get_irq(mixer_ctx->pdev, 0);
> + if (ret < 0)
> + return ret;
> + mixer_ctx->irq = ret;
>
> - ret = devm_request_irq(dev, res->start, mixer_irq_handler,
> - 0, "drm_mixer", mixer_ctx);
> + ret = devm_request_irq(dev, mixer_ctx->irq, mixer_irq_handler,
> + 0, "drm_mixer", mixer_ctx);
> if (ret) {
> dev_err(dev, "request interrupt failed.\n");
> return ret;
> }
> - mixer_ctx->irq = res->start;
>
> return 0;
> }
>