[PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[José Expósito]

Two drm_gem_shmem KUnit tests, drm_gem_shmem_test_get_pages_sgt() and
drm_gem_shmem_test_purge(), intermittently fail on ppc64le and s390x CI
with a DMA address overflow warning followed by -EIO:

  DMA addr 0x00000001130b0000+65536 overflow (mask ffffffff, bus limit 0).
  Expected sgt is not error, but is: -5

Both tests call `drm_gem_shmem_get_pages_sgt()`, which internally pins
backing pages and DMA-maps them via `dma_map_sgtable()`. The DMA mapping
path is:

  drm_gem_shmem_test_purge()
    drm_gem_shmem_get_pages_sgt()
      drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
        dma_map_sgtable()                  [mapping.c]
          __dma_map_sg_attrs()
            dma_direct_map_sg()            [direct.c]
              dma_direct_map_phys()        [kernel/dma/direct.h]
                dma_capable()              Checks addr against DMA mask
                  -> FAILS: addr > 0xFFFFFFFF

KUnit devices are initialized with a 32-bit DMA mask
(`DMA_BIT_MASK(32)`) in `lib/kunit/device.c`. On systems where the kernel
allocates backing pages at physical addresses above 4GB, `dma_capable()`
returns false because the address exceeds the 32-bit mask. The `dma_set_mask()`
function updates `*dev->dma_mask` to the given value; setting it to
`DMA_BIT_MASK(64)` allows any physical address to pass the check.

The failure is intermittent because pages may or may not be allocated
above 4GB on any given run depend on memory pressure.

A third test in the same suite, `drm_gem_shmem_test_obj_create_private`,
already calls `dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64))` before its
DMA mapping. This series applies the same fix to the two remaining tests.

José Expósito (2):
  drm/tests: shmem: Set DMA mask to 64-bit in
    drm_gem_shmem_test_get_pages_sgt
  drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge

 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

-- 
2.54.0

[PATCH 1/2] drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_get_pages_sgt

[José Expósito]

From: José Expósito <jose.exposito@redhat.com>

drm_gem_shmem_test_get_pages_sgt intermittently fails on ppc64le and
s390x CI systems with a DMA address overflow: [1]

  DMA addr 0x00000001b6110000+65536 overflow (mask ffffffff, bus limit 0)
  WARNING: kernel/dma/direct.h:114 dma_direct_map_phys+0x298/0x300

  drm_gem_shmem_test_get_pages_sgt: ASSERTION FAILED at
    drivers/gpu/drm/tests/drm_gem_shmem_test.c:255
    Expected sgt is not error, but is: -5

The call chain leading to the failure is:

  drm_gem_shmem_test_get_pages_sgt()
    drm_gem_shmem_get_pages_sgt()
      drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
        dma_map_sgtable()                  [mapping.c]
          __dma_map_sg_attrs()
            dma_direct_map_sg()            [direct.c]
              dma_direct_map_phys()        [kernel/dma/direct.h]
                dma_capable()              Checks addr against DMA mask
                  -> FAILS: addr > 0xFFFFFFFF

The root cause is that KUnit devices are initialized with a 32-bit DMA
mask (DMA_BIT_MASK(32)) in lib/kunit/device.c. On ppc64le and s390x
systems with physical memory above 4GB, page allocations can land at
addresses that exceed this mask. When drm_gem_shmem_get_pages_sgt()
attempts to DMA-map these pages via dma_map_sgtable(), the DMA layer
rejects the mapping because the physical address overflows the 32-bit
mask.

The failure is intermittent because pages may or may not be allocated
above 4GB on any given run depend on memory pressure.

Fix by setting a 64-bit DMA mask on the device before calling
drm_gem_shmem_get_pages_sgt(), following the same pattern already used
in drm_gem_shmem_test_obj_create_private().

[1] https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/2643976103/test_ppc64le/15128551933/artifacts/jobwatch/logs/recipes/21561041/tasks/220716705/results/1014628163/logs/dmesg.log

Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem")
Closes: https://datawarehouse.cki-project.org/issue/3184
Assisted-by: Claude:claude-4.6-opus
Signed-off-by: José Expósito <jose.exposito@redhat.com>
---
 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 44a190109249..c217a9ec7240 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -250,7 +250,11 @@ static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
 	struct drm_gem_shmem_object *shmem;
 	struct sg_table *sgt;
 	struct scatterlist *sg;
-	unsigned int si, ret, len = 0;
+	unsigned int si, len = 0;
+	int ret;
+
+	ret = dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64));
+	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
-- 
2.54.0

[PATCH 2/2] drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge

[José Expósito]

From: José Expósito <jose.exposito@redhat.com>

drm_gem_shmem_test_purge intermittently fails on ppc64le and s390x CI
systems with a DMA address overflow: [1]

  DMA addr 0x0000000100307000+4096 overflow (mask ffffffff, bus limit 0)
  WARNING: kernel/dma/direct.h:114 dma_direct_map_sg+0x778/0x920

  drm_gem_shmem_test_purge: ASSERTION FAILED at
    drivers/gpu/drm/tests/drm_gem_shmem_test.c:330
    Expected sgt is not error, but is: -5

The call chain leading to the failure is:

  drm_gem_shmem_test_purge()
    drm_gem_shmem_get_pages_sgt()
      drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
        dma_map_sgtable()                  [mapping.c]
          __dma_map_sg_attrs()
            dma_direct_map_sg()            [direct.c]
              dma_direct_map_phys()        [kernel/dma/direct.h]
                dma_capable()              Checks addr against DMA mask
                  -> FAILS: addr > 0xFFFFFFFF

The root cause is that KUnit devices are initialized with a 32-bit DMA
mask (DMA_BIT_MASK(32)) in lib/kunit/device.c. On ppc64le and s390x
systems with physical memory above 4GB, page allocations can land at
addresses that exceed this mask. When drm_gem_shmem_get_pages_sgt()
attempts to DMA-map these pages via dma_map_sgtable(), the DMA layer
rejects the mapping because the physical address overflows the 32-bit
mask.

The failure is intermittent because pages may or may not be allocated
above 4GB on any given run depend on memory pressure.

Fix by setting a 64-bit DMA mask on the device before calling
drm_gem_shmem_get_pages_sgt(), following the same pattern already used
in drm_gem_shmem_test_obj_create_private().

[1] https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/2643976103/test_s390x/15128551935/artifacts/jobwatch/logs/recipes/21561049/tasks/220716793/results/1014626315/logs/dmesg.log

Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem")
Closes: https://datawarehouse.cki-project.org/issue/5345
Assisted-by: Claude:claude-4.6-opus
Signed-off-by: José Expósito <jose.exposito@redhat.com>
---
 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index c217a9ec7240..66dea51ac456 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -325,6 +325,9 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
 	struct sg_table *sgt;
 	int ret;
 
+	ret = dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64));
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
 	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
 
-- 
2.54.0

Re: [PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[Thomas Zimmermann]

Hi

Am 03.07.26 um 08:34 schrieb José Expósito:
> Two drm_gem_shmem KUnit tests, drm_gem_shmem_test_get_pages_sgt() and
> drm_gem_shmem_test_purge(), intermittently fail on ppc64le and s390x CI
> with a DMA address overflow warning followed by -EIO:
>
>    DMA addr 0x00000001130b0000+65536 overflow (mask ffffffff, bus limit 0).
>    Expected sgt is not error, but is: -5
>
> Both tests call `drm_gem_shmem_get_pages_sgt()`, which internally pins
> backing pages and DMA-maps them via `dma_map_sgtable()`. The DMA mapping
> path is:
>
>    drm_gem_shmem_test_purge()
>      drm_gem_shmem_get_pages_sgt()
>        drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
>          dma_map_sgtable()                  [mapping.c]
>            __dma_map_sg_attrs()
>              dma_direct_map_sg()            [direct.c]
>                dma_direct_map_phys()        [kernel/dma/direct.h]
>                  dma_capable()              Checks addr against DMA mask
>                    -> FAILS: addr > 0xFFFFFFFF
>
> KUnit devices are initialized with a 32-bit DMA mask
> (`DMA_BIT_MASK(32)`) in `lib/kunit/device.c`. On systems where the kernel
> allocates backing pages at physical addresses above 4GB, `dma_capable()`
> returns false because the address exceeds the 32-bit mask. The `dma_set_mask()`
> function updates `*dev->dma_mask` to the given value; setting it to
> `DMA_BIT_MASK(64)` allows any physical address to pass the check.
>
> The failure is intermittent because pages may or may not be allocated
> above 4GB on any given run depend on memory pressure.
>
> A third test in the same suite, `drm_gem_shmem_test_obj_create_private`,
> already calls `dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64))` before its
> DMA mapping. This series applies the same fix to the two remaining tests.

Instead of doing whack-a-mole, is it possible to move the existing fix 
from drm_gem_shmem_test_obj_create_private() to _test_init at [1] ? The 
DMA mask would then be the same on all tests. [1] 
https://elixir.bootlin.com/linux/v7.1.2/source/drivers/gpu/drm/tests/drm_gem_shmem_test.c#L359 
Best regards Thomas
>
> José Expósito (2):
>    drm/tests: shmem: Set DMA mask to 64-bit in
>      drm_gem_shmem_test_get_pages_sgt
>    drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge
>
>   drivers/gpu/drm/tests/drm_gem_shmem_test.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

Re: [PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[José Expósito]

Hi Thomas,

Thanks for your review.

On Fri, Jul 03, 2026 at 08:53:30AM +0200, Thomas Zimmermann wrote:
> Hi
> 
> Am 03.07.26 um 08:34 schrieb José Expósito:
> > Two drm_gem_shmem KUnit tests, drm_gem_shmem_test_get_pages_sgt() and
> > drm_gem_shmem_test_purge(), intermittently fail on ppc64le and s390x CI
> > with a DMA address overflow warning followed by -EIO:
> > 
> >    DMA addr 0x00000001130b0000+65536 overflow (mask ffffffff, bus limit 0).
> >    Expected sgt is not error, but is: -5
> > 
> > Both tests call `drm_gem_shmem_get_pages_sgt()`, which internally pins
> > backing pages and DMA-maps them via `dma_map_sgtable()`. The DMA mapping
> > path is:
> > 
> >    drm_gem_shmem_test_purge()
> >      drm_gem_shmem_get_pages_sgt()
> >        drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
> >          dma_map_sgtable()                  [mapping.c]
> >            __dma_map_sg_attrs()
> >              dma_direct_map_sg()            [direct.c]
> >                dma_direct_map_phys()        [kernel/dma/direct.h]
> >                  dma_capable()              Checks addr against DMA mask
> >                    -> FAILS: addr > 0xFFFFFFFF
> > 
> > KUnit devices are initialized with a 32-bit DMA mask
> > (`DMA_BIT_MASK(32)`) in `lib/kunit/device.c`. On systems where the kernel
> > allocates backing pages at physical addresses above 4GB, `dma_capable()`
> > returns false because the address exceeds the 32-bit mask. The `dma_set_mask()`
> > function updates `*dev->dma_mask` to the given value; setting it to
> > `DMA_BIT_MASK(64)` allows any physical address to pass the check.
> > 
> > The failure is intermittent because pages may or may not be allocated
> > above 4GB on any given run depend on memory pressure.
> > 
> > A third test in the same suite, `drm_gem_shmem_test_obj_create_private`,
> > already calls `dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64))` before its
> > DMA mapping. This series applies the same fix to the two remaining tests.
> 
> Instead of doing whack-a-mole, is it possible to move the existing fix from
> drm_gem_shmem_test_obj_create_private() to _test_init at [1] ? The DMA mask
> would then be the same on all tests. [1] https://elixir.bootlin.com/linux/v7.1.2/source/drivers/gpu/drm/tests/drm_gem_shmem_test.c#L359

Yes, I think it is possible. However, this is an intermittent failure that
I couldn't reproduce locally and I tried to reduce as much as possible the
risk of regression limitting the change to the 2 affected tests.

I'm afraid I don't have enough knoledge about GEM's internals to know if moving
the fix to the init function could introduce unwanted side-effects in the other
tests. If you think it'd be safe, I'll trust you and move it.

Jose

PS - Next week I'll be away from keyboard, so any change would need to wait a bit

> Best regards Thomas
> > 
> > José Expósito (2):
> >    drm/tests: shmem: Set DMA mask to 64-bit in
> >      drm_gem_shmem_test_get_pages_sgt
> >    drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge
> > 
> >   drivers/gpu/drm/tests/drm_gem_shmem_test.c | 9 ++++++++-
> >   1 file changed, 8 insertions(+), 1 deletion(-)
> > 
> 
> -- 
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
> GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
> 
> 

Re: [PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[Thomas Zimmermann]

Hi José
Am 03.07.26 um 11:00 schrieb José Expósito:
> Hi Thomas,
>
> Thanks for your review.
>
> On Fri, Jul 03, 2026 at 08:53:30AM +0200, Thomas Zimmermann wrote:
>> Hi
>>
>> Am 03.07.26 um 08:34 schrieb José Expósito:
>>> Two drm_gem_shmem KUnit tests, drm_gem_shmem_test_get_pages_sgt() and
>>> drm_gem_shmem_test_purge(), intermittently fail on ppc64le and s390x CI
>>> with a DMA address overflow warning followed by -EIO:
>>>
>>>     DMA addr 0x00000001130b0000+65536 overflow (mask ffffffff, bus limit 0).
>>>     Expected sgt is not error, but is: -5
>>>
>>> Both tests call `drm_gem_shmem_get_pages_sgt()`, which internally pins
>>> backing pages and DMA-maps them via `dma_map_sgtable()`. The DMA mapping
>>> path is:
>>>
>>>     drm_gem_shmem_test_purge()
>>>       drm_gem_shmem_get_pages_sgt()
>>>         drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
>>>           dma_map_sgtable()                  [mapping.c]
>>>             __dma_map_sg_attrs()
>>>               dma_direct_map_sg()            [direct.c]
>>>                 dma_direct_map_phys()        [kernel/dma/direct.h]
>>>                   dma_capable()              Checks addr against DMA mask
>>>                     -> FAILS: addr > 0xFFFFFFFF
>>>
>>> KUnit devices are initialized with a 32-bit DMA mask
>>> (`DMA_BIT_MASK(32)`) in `lib/kunit/device.c`. On systems where the kernel
>>> allocates backing pages at physical addresses above 4GB, `dma_capable()`
>>> returns false because the address exceeds the 32-bit mask. The `dma_set_mask()`
>>> function updates `*dev->dma_mask` to the given value; setting it to
>>> `DMA_BIT_MASK(64)` allows any physical address to pass the check.
>>>
>>> The failure is intermittent because pages may or may not be allocated
>>> above 4GB on any given run depend on memory pressure.
>>>
>>> A third test in the same suite, `drm_gem_shmem_test_obj_create_private`,
>>> already calls `dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64))` before its
>>> DMA mapping. This series applies the same fix to the two remaining tests.
>> Instead of doing whack-a-mole, is it possible to move the existing fix from
>> drm_gem_shmem_test_obj_create_private() to _test_init at [1] ? The DMA mask
>> would then be the same on all tests. [1] https://elixir.bootlin.com/linux/v7.1.2/source/drivers/gpu/drm/tests/drm_gem_shmem_test.c#L359
> Yes, I think it is possible. However, this is an intermittent failure that
> I couldn't reproduce locally and I tried to reduce as much as possible the
> risk of regression limitting the change to the 2 affected tests.
>
> I'm afraid I don't have enough knoledge about GEM's internals to know if moving
> the fix to the init function could introduce unwanted side-effects in the other
> tests. If you think it'd be safe, I'll trust you and move it.

Please do. I don't see why it should not work, and it's an easy revert 
it doesn't.

Best regards
Thomas

>
> Jose
>
> PS - Next week I'll be away from keyboard, so any change would need to wait a bit
>
>> Best regards Thomas
>>> José Expósito (2):
>>>     drm/tests: shmem: Set DMA mask to 64-bit in
>>>       drm_gem_shmem_test_get_pages_sgt
>>>     drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge
>>>
>>>    drivers/gpu/drm/tests/drm_gem_shmem_test.c | 9 ++++++++-
>>>    1 file changed, 8 insertions(+), 1 deletion(-)
>>>
>> -- 
>> --
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
>> GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
>>
>>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

Re: [PATCH 0/2] drm/tests: shmem: Fix intermittent DMA overflow on ppc64le/s390x

[José Expósito]

On Fri, Jul 03, 2026 at 12:32:18PM +0200, Thomas Zimmermann wrote:
> Hi José
> Am 03.07.26 um 11:00 schrieb José Expósito:
> > Hi Thomas,
> > 
> > Thanks for your review.
> > 
> > On Fri, Jul 03, 2026 at 08:53:30AM +0200, Thomas Zimmermann wrote:
> > > Hi
> > > 
> > > Am 03.07.26 um 08:34 schrieb José Expósito:
> > > > Two drm_gem_shmem KUnit tests, drm_gem_shmem_test_get_pages_sgt() and
> > > > drm_gem_shmem_test_purge(), intermittently fail on ppc64le and s390x CI
> > > > with a DMA address overflow warning followed by -EIO:
> > > > 
> > > >     DMA addr 0x00000001130b0000+65536 overflow (mask ffffffff, bus limit 0).
> > > >     Expected sgt is not error, but is: -5
> > > > 
> > > > Both tests call `drm_gem_shmem_get_pages_sgt()`, which internally pins
> > > > backing pages and DMA-maps them via `dma_map_sgtable()`. The DMA mapping
> > > > path is:
> > > > 
> > > >     drm_gem_shmem_test_purge()
> > > >       drm_gem_shmem_get_pages_sgt()
> > > >         drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c]
> > > >           dma_map_sgtable()                  [mapping.c]
> > > >             __dma_map_sg_attrs()
> > > >               dma_direct_map_sg()            [direct.c]
> > > >                 dma_direct_map_phys()        [kernel/dma/direct.h]
> > > >                   dma_capable()              Checks addr against DMA mask
> > > >                     -> FAILS: addr > 0xFFFFFFFF
> > > > 
> > > > KUnit devices are initialized with a 32-bit DMA mask
> > > > (`DMA_BIT_MASK(32)`) in `lib/kunit/device.c`. On systems where the kernel
> > > > allocates backing pages at physical addresses above 4GB, `dma_capable()`
> > > > returns false because the address exceeds the 32-bit mask. The `dma_set_mask()`
> > > > function updates `*dev->dma_mask` to the given value; setting it to
> > > > `DMA_BIT_MASK(64)` allows any physical address to pass the check.
> > > > 
> > > > The failure is intermittent because pages may or may not be allocated
> > > > above 4GB on any given run depend on memory pressure.
> > > > 
> > > > A third test in the same suite, `drm_gem_shmem_test_obj_create_private`,
> > > > already calls `dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64))` before its
> > > > DMA mapping. This series applies the same fix to the two remaining tests.
> > > Instead of doing whack-a-mole, is it possible to move the existing fix from
> > > drm_gem_shmem_test_obj_create_private() to _test_init at [1] ? The DMA mask
> > > would then be the same on all tests. [1] https://elixir.bootlin.com/linux/v7.1.2/source/drivers/gpu/drm/tests/drm_gem_shmem_test.c#L359
> > Yes, I think it is possible. However, this is an intermittent failure that
> > I couldn't reproduce locally and I tried to reduce as much as possible the
> > risk of regression limitting the change to the 2 affected tests.
> > 
> > I'm afraid I don't have enough knoledge about GEM's internals to know if moving
> > the fix to the init function could introduce unwanted side-effects in the other
> > tests. If you think it'd be safe, I'll trust you and move it.
> 
> Please do. I don't see why it should not work, and it's an easy revert it
> doesn't.

I just sent v2 with the suggested change. I run the test in several
architectures and I didn't run into any issue:

https://lore.kernel.org/dri-devel/20260703142749.4099-1-jose.exposito89@gmail.com/

Thanks,
Jose

> 
> Best regards
> Thomas
> 
> > 
> > Jose
> > 
> > PS - Next week I'll be away from keyboard, so any change would need to wait a bit
> > 
> > > Best regards Thomas
> > > > José Expósito (2):
> > > >     drm/tests: shmem: Set DMA mask to 64-bit in
> > > >       drm_gem_shmem_test_get_pages_sgt
> > > >     drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem_test_purge
> > > > 
> > > >    drivers/gpu/drm/tests/drm_gem_shmem_test.c | 9 ++++++++-
> > > >    1 file changed, 8 insertions(+), 1 deletion(-)
> > > > 
> > > -- 
> > > --
> > > Thomas Zimmermann
> > > Graphics Driver Developer
> > > SUSE Software Solutions Germany GmbH
> > > Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
> > > GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
> > > 
> > > 
> 
> -- 
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
> GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
> 
>