[igt-dev] [PATCH i-g-t] [RFC] tests/kms_prime: Aligned pitch to 64 byte for Intel platforms

[Srinivas, Vidya]

Hello Ville,

Apologies for bothering you.
Kms_prime goes through vgem_gem_dumb_create where the pitch gets calculated which is not 64 byte aligned.

kms_prime->vgem_gem_dumb_create->intel_framebuffer_init which reports plane 0 pitch (5464) must be at least 64 byte aligned.

We have submitted this patch for kernel https://patchwork.freedesktop.org/patch/436199/ also for the same.
If we try to align stride in IGT after it gets back from vgem_gem_dumb_ioctl, Kernel gives error - [drm:intel_fill_fb_info] fb too big for bo (need 4227072 bytes, have 4198400 bytes).

As a workaround (if the above kernel patch does not go through) we submitted this https://patchwork.freedesktop.org/patch/435794/.

Can you kindly help suggest which is the better way? If not both - kindly guide us how we can address this issue. Thank you so much.

Regards
Vidya

-----Original Message-----
From: Srinivas, Vidya 
Sent: Monday, May 31, 2021 8:18 PM
To: 'Ville Syrjälä' <ville.syrjala at linux.intel.com>
Cc: intel-gfx at lists.freedesktop.org; igt-dev at lists.freedesktop.org; Lin, Charlton <Charlton.Lin at intel.com>
Subject: RE: [igt-dev] [PATCH i-g-t] [RFC] tests/kms_prime: Aligned pitch to 64 byte for Intel platforms

Hello Ville,

Thank you very much.
Before reaching our i915's i915_gem_dumb_create, it goes to vgem_gem_dumb_create for kms_prime.

The pitch gets calculated there and it is not 64 byte aligned. Due to this, intel_framebuffer_init reports "pitch must be 64 byte aligned"
and framebuffer creation fails. I tried submitting vgem patch where 64 byte alignment can be done in vgem_gem_dumb_create and that also passes. But we did not get approval yet as few of them felt, vgem is generic and other platforms might fail if we do 64 byte alignment there.

Kindly suggest. Thanks a lot.

Regards
Vidya

-----Original Message-----
From: Ville Syrjälä <ville.syrjala at linux.intel.com>
Sent: Monday, May 31, 2021 7:48 PM
To: Srinivas, Vidya <vidya.srinivas at intel.com>
Cc: intel-gfx at lists.freedesktop.org; igt-dev at lists.freedesktop.org; Lin, Charlton <charlton.lin at intel.com>
Subject: Re: [igt-dev] [PATCH i-g-t] [RFC] tests/kms_prime: Aligned pitch to 64 byte for Intel platforms

On Fri, May 28, 2021 at 10:04:03AM +0530, Vidya Srinivas wrote:
> For Intel platforms, pitch needs to be 64 byte aligned.
> Kernel code vgem_gem_dumb_create which is platform generic code doesnt 
> do the alignment. This causes frame buffer creation to fail on Intel 
> platforms where the pitch is not 64 byte aligned.
> 
> tests: test run on Intel platforms with panel resolution 1366x768
> 
> Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
> ---
>  tests/kms_prime.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/kms_prime.c b/tests/kms_prime.c index
> 8cb2ca2a9dc3..fdc941fe8100 100644
> --- a/tests/kms_prime.c
> +++ b/tests/kms_prime.c
> @@ -51,6 +51,8 @@ static struct {
>  	{ .r = 1.0, .g = 0.0, .b = 0.0, .color = 0xffff0000 },  };
>  
> +bool check_platform;
> +
>  IGT_TEST_DESCRIPTION("Prime tests, focusing on KMS side");
>  
>  static bool has_prime_import(int fd)
> @@ -101,7 +103,7 @@ static void prepare_scratch(int exporter_fd, struct dumb_bo *scratch,
>  	scratch->bpp = 32;
>  
>  	scratch->handle = kmstest_dumb_create(exporter_fd,
> -			scratch->width,
> +			check_platform? ALIGN(scratch->width, 64): scratch->width,

The dumb_create ioctl already does this for us.

>  			scratch->height,
>  			scratch->bpp,
>  			&scratch->pitch,
> @@ -262,6 +264,7 @@ igt_main
>  
>  		/* ANY = anything that is not VGEM */
>  		first_fd = __drm_open_driver_another(0, DRIVER_ANY | DRIVER_VGEM);
> +		check_platform = is_i915_device(first_fd);
>  		igt_require(first_fd >= 0);
>  
>  		second_fd = __drm_open_driver_another(1, DRIVER_ANY | DRIVER_VGEM);
> --
> 2.7.4
> 
> _______________________________________________
> igt-dev mailing list
> igt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/igt-dev

--
Ville Syrjälä
Intel