[igt-dev] [PATCH i-g-t 4/4] tests: Add nouveau-crc tests

[Petri Latvala]

On Tue, Mar 17, 2020 at 09:00:47PM -0400, Lyude wrote:
> From: Lyude Paul <lyude at redhat.com>
> 
> We're finally getting CRC support in nouveau, so let's start testing
> this in igt as well! While the normal CRC capture tests are nice,
> there's a number of Nvidia-specific hardware characteristics that we
> need to test as well.
> 
> The most important one is known as a "notifier context flip". Basically,
> Nvidia GPUs store generated CRCs in an allocated memory region, referred
> to as the notifier context, that the driver programs itself. Strangely,
> this region can only hold a limited number of CRC entries, and once it
> runs out of available entries the hardware simply sets an overrun bit
> and stops writing any new CRC entries.
> 
> Since igt-gpu-tools doesn't really have an expectation of only being
> able to grab a limited number of CRCs, we work around this in nouveau by
> allocating two separate CRC notifier regions each time we start
> capturing CRCs, and then flip between them whenever we get close to
> filling our currently programmed notifier context. While this keeps the
> number of CRC entries we lose to an absolute minimum, we are guaranteed
> to lose exactly one CRC entry between context flips. Thus, we add some
> tests to ensure that nouveau handles these flips correctly
> (pipe-[A-F]-ctx-flip-detection), and that igt itself is also able to
> handle them correctly (pipe-[A-F]-ctx-flip-skip-current-frame). Since
> these tests use a debugfs interface to manually control the notifier
> context flip threshold, we also add one test to ensure that any flip
> thresholds we set are cleared after a single CRC capture
> (ctx-flip-threshold-reset-after-capture).
> 
> In addition, we also add some simple tests to test Nvidia-specific CRC
> sources.
> 
> Signed-off-by: Lyude Paul <lyude at redhat.com>
> ---
>  lib/drmtest.c       |  10 ++
>  lib/drmtest.h       |   2 +
>  tests/meson.build   |   1 +
>  tests/nouveau_crc.c | 396 ++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 409 insertions(+)
>  create mode 100644 tests/nouveau_crc.c
> 
> diff --git a/lib/drmtest.c b/lib/drmtest.c
> index 1fc39925..53c01754 100644
> --- a/lib/drmtest.c
> +++ b/lib/drmtest.c
> @@ -112,6 +112,11 @@ bool is_i915_device(int fd)
>  	return __is_device(fd, "i915");
>  }
>  
> +bool is_nouveau_device(int fd)
> +{
> +	return __is_device(fd, "nouveau");
> +}
> +
>  bool is_vc4_device(int fd)
>  {
>  	return __is_device(fd, "vc4");
> @@ -537,6 +542,11 @@ void igt_require_intel(int fd)
>  	igt_require(is_i915_device(fd) && has_known_intel_chipset(fd));
>  }
>  
> +void igt_require_nouveau(int fd)
> +{
> +	igt_require(is_nouveau_device(fd));
> +}
> +
>  void igt_require_vc4(int fd)
>  {
>  	igt_require(is_vc4_device(fd));
> diff --git a/lib/drmtest.h b/lib/drmtest.h
> index 632c616b..4937e9d2 100644
> --- a/lib/drmtest.h
> +++ b/lib/drmtest.h
> @@ -97,10 +97,12 @@ void gem_quiescent_gpu(int fd);
>  
>  void igt_require_amdgpu(int fd);
>  void igt_require_intel(int fd);
> +void igt_require_nouveau(int fd);
>  void igt_require_vc4(int fd);
>  
>  bool is_amdgpu_device(int fd);
>  bool is_i915_device(int fd);
> +bool is_nouveau_device(int fd);
>  bool is_vc4_device(int fd);
>  
>  /**
> diff --git a/tests/meson.build b/tests/meson.build
> index 7629afde..9ff74cc6 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -70,6 +70,7 @@ test_progs = [
>  	'kms_vblank',
>  	'kms_vrr',
>  	'meta_test',
> +	'nouveau_crc',
>  	'panfrost_get_param',
>  	'panfrost_gem_new',
>  	'panfrost_prime',
> diff --git a/tests/nouveau_crc.c b/tests/nouveau_crc.c
> new file mode 100644
> index 00000000..09e17a6f
> --- /dev/null
> +++ b/tests/nouveau_crc.c
> @@ -0,0 +1,396 @@
> +/*
> + * Copyright © 2019 Red Hat Inc.

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-- 
Petri Latvala