Re: [PATCH v2] drm/ast: use managed devres functions

From: Philipp Stanner
Date: Fri Nov 10 2023 - 14:33:00 EST


On Fri, 2023-11-03 at 19:25 +0100, Philipp Stanner wrote:
> Currently, tha ast-driver just maps the PCI-dev's regions with
> pcim_iomap(). It does not actually reserve the regions exclusively
> with, e.g., pci_request_regions().
>
> Replace the calls to pcim_iomap() with ones to pcim_iomap_regions()
> to
> reserve and map the regions simultaneously.
>
> Suggested-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>

Thinking about this once more, I guess we could postpone merging it.

I'm a bit unhappy with the pcim_* functions as they're currently
implemented and might soon start working on a replacement.

Depending on that work, this Patch here might soon be obsolete /
outdated anyways.

But merging wouldn't hurt on the other hand, as I have to send a new
one in any case. I leave that up to the maintainer.

See also here [1] if interested.

P.

[1] https://lore.kernel.org/all/84be1049e41283cf8a110267646320af9ffe59fe.camel@xxxxxxxxxx/


> ---
> Changes in v2:
> - Remove unnecessary return code checks for pcim_iomap_regions()
>   (Jocelyn)
>
> Thx Jocelyn for the kind review
> ---
>  drivers/gpu/drm/ast/ast_main.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/ast/ast_main.c
> b/drivers/gpu/drm/ast/ast_main.c
> index dae365ed3969..8b714b99f9d6 100644
> --- a/drivers/gpu/drm/ast/ast_main.c
> +++ b/drivers/gpu/drm/ast/ast_main.c
> @@ -444,9 +444,11 @@ struct ast_device *ast_device_create(const
> struct drm_driver *drv,
>         if (ret)
>                 return ERR_PTR(ret);
>  
> -       ast->regs = pcim_iomap(pdev, 1, 0);
> -       if (!ast->regs)
> -               return ERR_PTR(-EIO);
> +       ret = pcim_iomap_regions(pdev, BIT(1), 0);
> +       if (ret)
> +               return ERR_PTR(ret);
> +
> +       ast->regs = pcim_iomap_table(pdev)[1];
>  
>         /*
>          * After AST2500, MMIO is enabled by default, and it should
> be adopted
> @@ -461,9 +463,10 @@ struct ast_device *ast_device_create(const
> struct drm_driver *drv,
>  
>         /* "map" IO regs if the above hasn't done so already */
>         if (!ast->ioregs) {
> -               ast->ioregs = pcim_iomap(pdev, 2, 0);
> -               if (!ast->ioregs)
> -                       return ERR_PTR(-EIO);
> +               ret = pcim_iomap_regions(pdev, BIT(2), 0);
> +               if (ret)
> +                       return ERR_PTR(ret);
> +               ast->ioregs = pcim_iomap_table(pdev)[2];
>         }
>  
>         if (!ast_is_vga_enabled(dev)) {