It seems like the device sometimes leaves part of the
sense buffer uninitialized. This causes massive problems with swiotlb where
any previous initialization of the sense buffer by the scsi middle-layer is
not propagated to the device since we use DMA_FROM_DEVICE when dma-mapping
the sense buffer. Fix this by specifying DMA_BIDIRECTIONAL instead. Makes the
scsi errors go away.
Tested using a bonnie++ run on an swiotlb=force booted kernel.
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
[jgill@xxxxxxxxxx: Forwarding patch on behalf of thellstrom]
Acked-by: jgill@xxxxxxxxxx
---
drivers/scsi/vmw_pvscsi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index fa2748f..c179a5d 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -429,7 +429,7 @@ static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
}
if (cmd->sense_buffer)
dma_unmap_single(&adapter->dev->dev, ctx->sensePA,
- SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+ SCSI_SENSE_BUFFERSIZE, DMA_BIDIRECTIONAL);
}
static int pvscsi_allocate_rings(struct pvscsi_adapter *adapter)
@@ -714,7 +714,7 @@ static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
if (cmd->sense_buffer) {
ctx->sensePA = dma_map_single(&adapter->dev->dev,
cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE,
- DMA_FROM_DEVICE);
+ DMA_BIDIRECTIONAL);
if (dma_mapping_error(&adapter->dev->dev, ctx->sensePA)) {
scmd_printk(KERN_DEBUG, cmd,
"vmw_pvscsi: Failed to map sense buffer for DMA.\n");
@@ -746,7 +746,7 @@ static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
if (cmd->sense_buffer) {
dma_unmap_single(&adapter->dev->dev, ctx->sensePA,
SCSI_SENSE_BUFFERSIZE,
- DMA_FROM_DEVICE);
+ DMA_BIDIRECTIONAL);
ctx->sensePA = 0;
}
return -ENOMEM;
--
2.7.4
