On Sun, Oct 20, 2019 at 07:10:27PM -0700, Bart Van Assche wrote: > If dev->dma_device->params == NULL then the maximum DMA segment size is > 64 KB. See also the dma_get_max_seg_size() implementation. This patch > fixes the following kernel warning: > > DMA-API: infiniband rxe0: mapping sg segment longer than device claims to support [len=126976] [max=65536] > WARNING: CPU: 4 PID: 4848 at kernel/dma/debug.c:1220 debug_dma_map_sg+0x3d9/0x450 > RIP: 0010:debug_dma_map_sg+0x3d9/0x450 > Call Trace: > srp_queuecommand+0x626/0x18d0 [ib_srp] > scsi_queue_rq+0xd02/0x13e0 [scsi_mod] > __blk_mq_try_issue_directly+0x2b3/0x3f0 > blk_mq_request_issue_directly+0xac/0xf0 > blk_insert_cloned_request+0xdf/0x170 > dm_mq_queue_rq+0x43d/0x830 [dm_mod] > __blk_mq_try_issue_directly+0x2b3/0x3f0 > blk_mq_request_issue_directly+0xac/0xf0 > blk_mq_try_issue_list_directly+0xb8/0x170 > blk_mq_sched_insert_requests+0x23c/0x3b0 > blk_mq_flush_plug_list+0x529/0x730 > blk_flush_plug_list+0x21f/0x260 > blk_mq_make_request+0x56b/0xf20 > generic_make_request+0x196/0x660 > submit_bio+0xae/0x290 > blkdev_direct_IO+0x822/0x900 > generic_file_direct_write+0x110/0x200 > __generic_file_write_iter+0x124/0x2a0 > blkdev_write_iter+0x168/0x270 > aio_write+0x1c4/0x310 > io_submit_one+0x971/0x1390 > __x64_sys_io_submit+0x12a/0x390 > do_syscall_64+0x6f/0x2e0 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Fixes: 0b5cb3300ae5 ("RDMA/srp: Increase max_segment_size") > Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> > include/rdma/ib_verbs.h | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h > index 6a47ba85c54c..e6c167d03aae 100644 > +++ b/include/rdma/ib_verbs.h > @@ -4043,9 +4043,7 @@ static inline void ib_dma_unmap_sg_attrs(struct ib_device *dev, > */ > static inline unsigned int ib_dma_max_seg_size(struct ib_device *dev) > { > - struct device_dma_parameters *p = dev->dma_device->dma_parms; > - > - return p ? p->max_segment_size : UINT_MAX; > + return dma_get_max_seg_size(dev->dma_device); > } Should we get rid of this wrapper? Jason