Re: [RFC PATCH 1/1] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb332()

From: Javier Martinez Canillas <javierm@redhat.com>
To: David Gow <davidgow@google.com>
Cc: "José Expósito" <jose.exposito89@gmail.com>,
	tzimmermann@suse.de, maarten.lankhorst@linux.intel.com,
	mripard@kernel.org, "David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"Daniel Latypov" <dlatypov@google.com>,
	"KUnit Development" <kunit-dev@googlegroups.com>
Subject: Re: [RFC PATCH 1/1] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb332()
Date: Thu, 2 Jun 2022 19:21:28 +0200	[thread overview]
Message-ID: <195c6865-d6f7-fbc4-6ee5-784c5c49d243@redhat.com> (raw)
In-Reply-To: <CABVgOSkCxu2xBnxwc6mO2AQaqzTbDf53PJzT2QvZNyLeumt5hg@mail.gmail.com>

Hello David,

On 6/2/22 19:07, David Gow wrote:
> On Thu, Jun 2, 2022 at 9:27 AM Javier Martinez Canillas

[snip]

>>
>> And doing that will also allow you to get rid of this, since just selecting
>> CONFIG_DRM_KUNIT_TEST=y would be enough for the tests built and run by KUnit.
>>
> 
> This is definitely something other KUnit tests (apparmor, elf, etc)
> are doing, and it's generally fine. You do lose the ability to build
> the tests as a separate module, though. (This is not usually a big
> problem, but there are some cases where it's useful.)
> 
> That being said, I don't think 'select' is enough of a problem that
> you should feel the need to refactor in this way just to avoid it.

Oh, yes I didn't want to imply that this was the main reason but just
pointed out that wouldn't even be needed if done that way. And it is
something that we want to do anyway IMO, since as mentioned it would
allow to test the static functions, which are the majority the format
helpers in that file.

> Given most of the other DRM drivers (as well as DRM_DEBUG_SELFTEST)
> are select-ing DRM_KMS_HELPER, it seems like a sensible enough thing
> to continue doing for the KUnit test. As Daniel pointed out, as a
> hidden option it was clearly always meant to be select-ed anyway.
>

Yes, it can be done from the DRM_KUNIT_TEST symbol or just have it set
(and any other needed DRM helper libraries tested by other suites) in
the .kunitconfig file.

I don't think is that important, since at the end that dependency will
have to be maintained in some place.

> Cheers,
> -- David
> 

-- 
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat