2023-03-07 21:51:56

by Javier Martinez Canillas

[permalink] [raw]
Subject: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts

There are DRM fourcc formats that have pixels smaller than a byte, but the
conversion_buf_size() function assumes that pixels are a multiple of bytes
and use the struct drm_format_info .cpp field to calculate the dst_pitch.

Instead, calculate it by using the bits per pixel (bpp) and divide it by 8
to account for formats that have sub-byte pixels.

Signed-off-by: Javier Martinez Canillas <[email protected]>
---
Tested by making sure that the following command still succeeds:

./tools/testing/kunit/kunit.py run \
--kunitconfig=drivers/gpu/drm/tests/.kunitconfig

Changes in v2:
- Drop an unused variable, that was pointed out by the kernel robot.

drivers/gpu/drm/tests/drm_format_helper_test.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 9536829c6e3a..84b5cc29c8fc 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -409,12 +409,15 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
const struct drm_rect *clip)
{
const struct drm_format_info *dst_fi = drm_format_info(dst_format);
+ unsigned int bpp;

if (!dst_fi)
return -EINVAL;

- if (!dst_pitch)
- dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];
+ if (!dst_pitch) {
+ bpp = drm_format_info_bpp(dst_fi, 0);
+ dst_pitch = DIV_ROUND_UP(drm_rect_width(clip) * bpp, 8);
+ }

return dst_pitch * drm_rect_height(clip);
}
--
2.39.2



2023-03-09 17:52:10

by Arthur Grillo

[permalink] [raw]
Subject: Re: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts


Hi,

On 07/03/23 18:50, Javier Martinez Canillas wrote:
> There are DRM fourcc formats that have pixels smaller than a byte, but the
> conversion_buf_size() function assumes that pixels are a multiple of bytes
> and use the struct drm_format_info .cpp field to calculate the dst_pitch.
>
> Instead, calculate it by using the bits per pixel (bpp) and divide it by 8
> to account for formats that have sub-byte pixels.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>
> ---
> Tested by making sure that the following command still succeeds:
>
> ./tools/testing/kunit/kunit.py run \
> --kunitconfig=drivers/gpu/drm/tests/.kunitconfig
>
> Changes in v2:
> - Drop an unused variable, that was pointed out by the kernel robot.
>
> drivers/gpu/drm/tests/drm_format_helper_test.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
> index 9536829c6e3a..84b5cc29c8fc 100644
> --- a/drivers/gpu/drm/tests/drm_format_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
> @@ -409,12 +409,15 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
> const struct drm_rect *clip)
> {
> const struct drm_format_info *dst_fi = drm_format_info(dst_format);
> + unsigned int bpp;
>
> if (!dst_fi)
> return -EINVAL;
>
> - if (!dst_pitch)
> - dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];
> + if (!dst_pitch) {
> + bpp = drm_format_info_bpp(dst_fi, 0);
> + dst_pitch = DIV_ROUND_UP(drm_rect_width(clip) * bpp, 8);
> + }
>
> return dst_pitch * drm_rect_height(clip);
> }

Ran it on UML, arm and powerpc with my patch above it, All looks good
:).

Reviewed-by: Arthur Grillo <[email protected]>

Thanks,
Grillo

2023-03-09 22:35:29

by Maíra Canal

[permalink] [raw]
Subject: Re: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts

On 3/7/23 18:50, Javier Martinez Canillas wrote:
> There are DRM fourcc formats that have pixels smaller than a byte, but the
> conversion_buf_size() function assumes that pixels are a multiple of bytes
> and use the struct drm_format_info .cpp field to calculate the dst_pitch.
>
> Instead, calculate it by using the bits per pixel (bpp) and divide it by 8
> to account for formats that have sub-byte pixels.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>

Reviewed-by: Maíra Canal <[email protected]>

Best Regards,
- Maíra Canal

> ---
> Tested by making sure that the following command still succeeds:
>
> ./tools/testing/kunit/kunit.py run \
> --kunitconfig=drivers/gpu/drm/tests/.kunitconfig
>
> Changes in v2:
> - Drop an unused variable, that was pointed out by the kernel robot.
>
> drivers/gpu/drm/tests/drm_format_helper_test.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
> index 9536829c6e3a..84b5cc29c8fc 100644
> --- a/drivers/gpu/drm/tests/drm_format_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
> @@ -409,12 +409,15 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
> const struct drm_rect *clip)
> {
> const struct drm_format_info *dst_fi = drm_format_info(dst_format);
> + unsigned int bpp;
>
> if (!dst_fi)
> return -EINVAL;
>
> - if (!dst_pitch)
> - dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];
> + if (!dst_pitch) {
> + bpp = drm_format_info_bpp(dst_fi, 0);
> + dst_pitch = DIV_ROUND_UP(drm_rect_width(clip) * bpp, 8);
> + }
>
> return dst_pitch * drm_rect_height(clip);
> }

2023-03-10 11:47:38

by Javier Martinez Canillas

[permalink] [raw]
Subject: Re: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts

Javier Martinez Canillas <[email protected]> writes:

> There are DRM fourcc formats that have pixels smaller than a byte, but the
> conversion_buf_size() function assumes that pixels are a multiple of bytes
> and use the struct drm_format_info .cpp field to calculate the dst_pitch.
>
> Instead, calculate it by using the bits per pixel (bpp) and divide it by 8
> to account for formats that have sub-byte pixels.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>
> ---

Pushed to drm-misc (drm-misc-next). Thanks!

--
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat


2023-03-16 16:31:12

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts

Hi Javier,

On Tue, Mar 7, 2023 at 10:54 PM Javier Martinez Canillas
<[email protected]> wrote:
> There are DRM fourcc formats that have pixels smaller than a byte, but the
> conversion_buf_size() function assumes that pixels are a multiple of bytes
> and use the struct drm_format_info .cpp field to calculate the dst_pitch.
>
> Instead, calculate it by using the bits per pixel (bpp) and divide it by 8
> to account for formats that have sub-byte pixels.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>
> ---
> Tested by making sure that the following command still succeeds:
>
> ./tools/testing/kunit/kunit.py run \
> --kunitconfig=drivers/gpu/drm/tests/.kunitconfig
>
> Changes in v2:
> - Drop an unused variable, that was pointed out by the kernel robot.

Thanks for your patch!

> --- a/drivers/gpu/drm/tests/drm_format_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
> @@ -409,12 +409,15 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
> const struct drm_rect *clip)
> {
> const struct drm_format_info *dst_fi = drm_format_info(dst_format);
> + unsigned int bpp;
>
> if (!dst_fi)
> return -EINVAL;
>
> - if (!dst_pitch)
> - dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];
> + if (!dst_pitch) {
> + bpp = drm_format_info_bpp(dst_fi, 0);
> + dst_pitch = DIV_ROUND_UP(drm_rect_width(clip) * bpp, 8);

I know I'm a bit late to the party, but here's actually a helper for that:

dst_pitch = drm_format_info_min_pitch(info, 0, drm_rect_width(clip));

> + }
>
> return dst_pitch * drm_rect_height(clip);
> }

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

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

2023-03-16 22:31:23

by Javier Martinez Canillas

[permalink] [raw]
Subject: Re: [PATCH v2] drm/format-helper: Make conversion_buf_size() support sub-byte pixel fmts

Geert Uytterhoeven <[email protected]> writes:

Hello Geert,

[...]

>> + if (!dst_pitch) {
>> + bpp = drm_format_info_bpp(dst_fi, 0);
>> + dst_pitch = DIV_ROUND_UP(drm_rect_width(clip) * bpp, 8);
>
> I know I'm a bit late to the party, but here's actually a helper for that:
>
> dst_pitch = drm_format_info_min_pitch(info, 0, drm_rect_width(clip));
>

Nice, I didn't notice this. I'll send a follow-up patch. Thanks!

--
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat