scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask

This change “scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask” (commit 1d94f06) in Linux kernel is authored by Lianbo Jiang <lijiang [at] redhat.com> on Mon May 27 08:59:34 2019 +0800.

Description of "scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask"

The change “scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask” introduces changes as follows.

scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask

When SME is enabled, the smartpqi driver won't work on the HP DL385 G10
machine, which causes the failure of kernel boot because it fails to
allocate pqi error buffer. Please refer to the kernel log:
....
[    9.431749] usbcore: registered new interface driver uas
[    9.441524] Microsemi PQI Driver (v1.1.4-130)
[    9.442956] i40e 0000:04:00.0: fw 6.70.48768 api 1.7 nvm 10.2.5
[    9.447237] smartpqi 0000:23:00.0: Microsemi Smart Family Controller found
         Starting dracut initqueue hook...
[  OK  ] Started Show Plymouth Boot Scre[    9.471654] Broadcom NetXtreme-C/E driver bnxt_en v1.9.1
en.
[  OK  ] Started Forward Password Requests to Plymouth Directory Watch.
[[0;[    9.487108] smartpqi 0000:23:00.0: failed to allocate PQI error buffer
....
[  139.050544] dracut-initqueue[949]: Warning: dracut-initqueue timeout - starting timeout scripts
[  139.589779] dracut-initqueue[949]: Warning: dracut-initqueue timeout - starting timeout scripts

Basically, the fact that the coherent DMA mask value wasn't set caused the
driver to fall back to SWIOTLB when SME is active.

For correct operation, lets call the dma_set_mask_and_coherent() to
properly set the mask for both streaming and coherent, in order to inform
the kernel about the devices DMA addressing capabilities.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Tested-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Linux kernel releases containing commit 1d94f06

The Linux kernel releases containing this commit are as follows.

Linux kernel code changes from "scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask"

There are 2 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index b17761eafca9..d6be4e8f4a8f 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -7291,7 +7291,7 @@ static int pqi_pci_init(struct pqi_ctrl_info *ctrl_info)
 	else
 		mask = DMA_BIT_MASK(32);
 
-	rc = dma_set_mask(&ctrl_info->pci_dev->dev, mask);
+	rc = dma_set_mask_and_coherent(&ctrl_info->pci_dev->dev, mask);
 	if (rc) {
 		dev_err(&ctrl_info->pci_dev->dev, "failed to set DMA mask\n");
 		goto disable_device;

The commit for this change in Linux stable tree is 1d94f06 (patch).

Last modified: 2020/02/08