scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask [Linux 4.14.129]

scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask [Linux 4.14.129]

This Linux kernel change "scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask" is included in the Linux 4.14.129 release. This change is authored by Lianbo Jiang <lijiang [at] redhat.com> on Mon May 27 08:59:34 2019 +0800. The commit for this change in Linux stable tree is 558ca95 (patch) which is from upstream commit 1d94f06. The same Linux upstream change may have been applied to various maintained Linux releases and you can find all Linux releases containing changes from upstream 1d94f06.

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

[ Upstream commit 1d94f06e7f5df4064ef336b7b710f50143b64a53 ]

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 <[email protected]>
Acked-by: Don Brace <[email protected]>
Tested-by: Don Brace <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

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 5ec2898..d34351c 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -6392,7 +6392,7 @@ 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;

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