Re: [PATCH v2 05/14] drm: Suppress intentional warning backtraces in scaling unit tests

[Guenter Roeck <linux@roeck-us.net>]

Hi,

On Mon, Mar 25, 2024 at 04:05:06PM -0300, Maíra Canal wrote:
> Hi Guenter,
> 
> On 3/25/24 14:52, Guenter Roeck wrote:
> > The drm_test_rect_calc_hscale and drm_test_rect_calc_vscale unit tests
> > intentionally trigger warning backtraces by providing bad parameters to
> > the tested functions. What is tested is the return value, not the existence
> > of a warning backtrace. Suppress the backtraces to avoid clogging the
> > kernel log.
> > 
> > Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
> > Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> > ---
> > - Rebased to v6.9-rc1
> > - Added Tested-by:, Acked-by:, and Reviewed-by: tags
> > 
> >   drivers/gpu/drm/tests/drm_rect_test.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c
> > index 76332cd2ead8..75614cb4deb5 100644
> > --- a/drivers/gpu/drm/tests/drm_rect_test.c
> > +++ b/drivers/gpu/drm/tests/drm_rect_test.c
> > @@ -406,22 +406,28 @@ KUNIT_ARRAY_PARAM(drm_rect_scale, drm_rect_scale_cases, drm_rect_scale_case_desc
> >   static void drm_test_rect_calc_hscale(struct kunit *test)
> >   {
> > +	DEFINE_SUPPRESSED_WARNING(drm_calc_scale);
> >   	const struct drm_rect_scale_case *params = test->param_value;
> >   	int scaling_factor;
> > +	START_SUPPRESSED_WARNING(drm_calc_scale);
> 
> I'm not sure if it is not that obvious only to me, but it would be nice
> to have a comment here, remembering that we provide bad parameters in
> some test cases.

Sure. Something like this ?

        /*
         * drm_rect_calc_hscale() generates a warning backtrace whenever bad
         * parameters are passed to it. This affects all unit tests with an
         * error code in expected_scaling_factor.
         */

Thanks,
Guenter