Re: [PATCH v2 11/25] drm/loongson: Compute dumb-buffer sizes with drm_mode_size_dumb()

[Sui Jingfeng <sui.jingfeng@linux.dev>]

Hi,

On 2025/1/9 22:57, Thomas Zimmermann wrote:
> Call drm_mode_size_dumb() to compute dumb-buffer scanline pitch and
> buffer size. Align the pitch according to hardware requirements.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Sui Jingfeng <suijingfeng@loongson.cn>
> Cc: Sui Jingfeng <sui.jingfeng@linux.dev>


Reviewed-by: Sui Jingfeng <sui.jingfeng@linux.dev>


> ---
>   drivers/gpu/drm/loongson/lsdc_gem.c | 29 ++++++++---------------------
>   1 file changed, 8 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/loongson/lsdc_gem.c b/drivers/gpu/drm/loongson/lsdc_gem.c
> index a720d8f53209..9f982b85301f 100644
> --- a/drivers/gpu/drm/loongson/lsdc_gem.c
> +++ b/drivers/gpu/drm/loongson/lsdc_gem.c
> @@ -6,6 +6,7 @@
>   #include <linux/dma-buf.h>
>   
>   #include <drm/drm_debugfs.h>
> +#include <drm/drm_dumb_buffers.h>
>   #include <drm/drm_file.h>
>   #include <drm/drm_gem.h>
>   #include <drm/drm_prime.h>
> @@ -204,45 +205,31 @@ int lsdc_dumb_create(struct drm_file *file, struct drm_device *ddev,
>   	const struct lsdc_desc *descp = ldev->descp;
>   	u32 domain = LSDC_GEM_DOMAIN_VRAM;
>   	struct drm_gem_object *gobj;
> -	size_t size;
> -	u32 pitch;
> -	u32 handle;
>   	int ret;
>   
> -	if (!args->width || !args->height)
> -		return -EINVAL;
> -
> -	if (args->bpp != 32 && args->bpp != 16)
> -		return -EINVAL;
> -
> -	pitch = args->width * args->bpp / 8;
> -	pitch = ALIGN(pitch, descp->pitch_align);
> -	size = pitch * args->height;
> -	size = ALIGN(size, PAGE_SIZE);
> +	ret = drm_mode_size_dumb(ddev, args, descp->pitch_align, 0);
> +	if (ret)
> +		return ret;
>   
>   	/* Maximum single bo size allowed is the half vram size available */
> -	if (size > ldev->vram_size / 2) {
> -		drm_err(ddev, "Requesting(%zuMiB) failed\n", size >> 20);
> +	if (args->size > ldev->vram_size / 2) {
> +		drm_err(ddev, "Requesting(%zuMiB) failed\n", (size_t)(args->size >> PAGE_SHIFT));
>   		return -ENOMEM;
>   	}
>   
> -	gobj = lsdc_gem_object_create(ddev, domain, size, false, NULL, NULL);
> +	gobj = lsdc_gem_object_create(ddev, domain, args->size, false, NULL, NULL);
>   	if (IS_ERR(gobj)) {
>   		drm_err(ddev, "Failed to create gem object\n");
>   		return PTR_ERR(gobj);
>   	}
>   
> -	ret = drm_gem_handle_create(file, gobj, &handle);
> +	ret = drm_gem_handle_create(file, gobj, &args->handle);
>   
>   	/* drop reference from allocate, handle holds it now */
>   	drm_gem_object_put(gobj);
>   	if (ret)
>   		return ret;
>   
> -	args->pitch = pitch;
> -	args->size = size;
> -	args->handle = handle;
> -
>   	return 0;
>   }
>   

-- 
Best regards,
Sui