[PATCH 4.19 082/306] scsi: dc395x: fix dma API usage in srb_done

From: Greg Kroah-Hartman
Date: Wed Nov 27 2019 - 16:28:26 EST


From: Christoph Hellwig <hch@xxxxxx>

[ Upstream commit 3a5bd7021184dec2946f2a4d7a8943f8a5713e52 ]

We can't just transfer ownership to the CPU and then unmap, as this will
break with swiotlb.

Instead unmap the command and sense buffer a little earlier in the I/O
completion handler and get rid of the pci_dma_sync_sg_for_cpu call
entirely.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/dc395x.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/dc395x.c b/drivers/scsi/dc395x.c
index 1ed2cd82129d2..08161df64ead5 100644
--- a/drivers/scsi/dc395x.c
+++ b/drivers/scsi/dc395x.c
@@ -3447,14 +3447,12 @@ static void srb_done(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
}
}

- if (dir != PCI_DMA_NONE && scsi_sg_count(cmd))
- pci_dma_sync_sg_for_cpu(acb->dev, scsi_sglist(cmd),
- scsi_sg_count(cmd), dir);
-
ckc_only = 0;
/* Check Error Conditions */
ckc_e:

+ pci_unmap_srb(acb, srb);
+
if (cmd->cmnd[0] == INQUIRY) {
unsigned char *base = NULL;
struct ScsiInqData *ptr;
@@ -3507,7 +3505,6 @@ static void srb_done(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
cmd, cmd->result);
srb_free_insert(acb, srb);
}
- pci_unmap_srb(acb, srb);

cmd->scsi_done(cmd);
waiting_process_next(acb);
--
2.20.1