diff mbox series

[v2,4/4] RDMA/core: Set DMA parameters correctly

Message ID 20191025225830.257535-5-bvanassche@acm.org (mailing list archive)
State Mainlined
Commit c9121262d57b8a3be4f08073546436ba0128ca6a
Delegated to: Jason Gunthorpe
Headers show
Series Fixes related to the DMA max_segment_size parameter | expand

Commit Message

Bart Van Assche Oct. 25, 2019, 10:58 p.m. UTC 
The dma_set_max_seg_size() call in setup_dma_device() does not have any
effect since device->dev.dma_parms is NULL. Fix this by initializing
device->dev.dma_parms first.

Cc: Michael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Adit Ranadive <aditr@vmware.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Selvin Xavier <selvin.xavier@broadcom.com>
Fixes: d10bcf947a3e ("RDMA/umem: Combine contiguous PAGE_SIZE regions in SGEs")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/infiniband/core/device.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index eb35b663a742..a93c23867fb5 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1196,9 +1196,21 @@  static void setup_dma_device(struct ib_device *device)
 		WARN_ON_ONCE(!parent);
 		device->dma_device = parent;
 	}
-	/* Setup default max segment size for all IB devices */
-	dma_set_max_seg_size(device->dma_device, SZ_2G);
 
+	if (!device->dev.dma_parms) {
+		if (parent) {
+			/*
+			 * The caller did not provide DMA parameters, so
+			 * 'parent' probably represents a PCI device. The PCI
+			 * core sets the maximum segment size to 64
+			 * KB. Increase this parameter to 2 GB.
+			 */
+			device->dev.dma_parms = parent->dma_parms;
+			dma_set_max_seg_size(device->dma_device, SZ_2G);
+		} else {
+			WARN_ON_ONCE(true);
+		}
+	}
 }
 
 /*