[PATCH] drm/test: fix the gem shmem test to map the sg table.

[Ruhl, Michael J]

>-----Original Message-----
>From: dri-devel <dri-devel-bounces at lists.freedesktop.org> On Behalf Of Dave
>Airlie
>Sent: Monday, July 15, 2024 4:36 AM
>To: dri-devel at lists.freedesktop.org
>Subject: [PATCH] drm/test: fix the gem shmem test to map the sg table.
>
>From: Dave Airlie <airlied at redhat.com>
>
>The test here creates an sg table, but never maps it, when
>we get to drm_gem_shmem_free, the helper tries to unmap and this
>causes warnings on some platforms and debug kernels.

This looks pretty straightforward...

However, should drm_gem_shmem_free() really give an error if the mapping
didn't happen?

I.e. just because you have an sgt pointer, should you also have a mapping?

If the errors are really just noise (form the specific platforms), and this patch is covering
for that, then:

Reviewed-by: Michael J. Ruhl <michael.j.ruhl at intel.com>

Thanks,

Mike

>This also sets a 64-bit dma mask, as I see an swiotlb warning if I
>stick with the default 32-bit one.
>
>Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by
>shmem")
>Cc: stable at vger.kernel.org
>Signed-off-by: Dave Airlie <airlied at redhat.com>
>---
> drivers/gpu/drm/tests/drm_gem_shmem_test.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
>diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
>b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
>index 91202e40cde9..eb3a7a84be90 100644
>--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
>+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
>@@ -102,6 +102,17 @@ static void
>drm_gem_shmem_test_obj_create_private(struct kunit *test)
>
> 	sg_init_one(sgt->sgl, buf, TEST_SIZE);
>
>+	/*
>+	 * Set the DMA mask to 64-bits and map the sgtables
>+	 * otherwise drm_gem_shmem_free will cause a warning
>+	 * on debug kernels.
>+	 * */
>+	ret = dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64));
>+	KUNIT_ASSERT_EQ(test, ret, 0);
>+
>+	ret = dma_map_sgtable(drm_dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
>+	KUNIT_ASSERT_EQ(test, ret, 0);
>+
> 	/* Init a mock DMA-BUF */
> 	buf_mock.size = TEST_SIZE;
> 	attach_mock.dmabuf = &buf_mock;
>--
>2.45.0