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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Action: no action X-Rspamd-Queue-Id: C7D647483D X-Spam-Flag: NO X-Spam-Score: -3.01 X-Spam-Level: X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; FREEMAIL_TO(0.00)[gmail.com]; FUZZY_RATELIMITED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; ARC_NA(0.00)[]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FREEMAIL_CC(0.00)[lists.freedesktop.org,vger.kernel.org,linux.intel.com,kernel.org,gmail.com,ffwll.ch,collabora.com]; RCVD_TLS_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_COUNT_TWO(0.00)[2]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:106:10:150:64:167:received]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; RCPT_COUNT_SEVEN(0.00)[9]; RCVD_VIA_SMTP_AUTH(0.00)[]; TAGGED_RCPT(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[bootlin.com:url,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo,suse.de:mid,suse.de:dkim,suse.com:url] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org 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)