From: Ondrej Zary <li...@rainbow-software.org>
The corruption is always the same: one byte missing at the beginning of
a 128 B block. It happens only with slow Quantum LPS 240 drive, not with
faster IBM DORS-32160. It's not clear what causes this. Documentation
for the DTC436 chip has not been made available. Hence this workaround.
Signed-off-by: Finn Thain <fth...@telegraphics.com.au>
---
drivers/scsi/g_NCR5380.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index dedaed2d16e4..5fd227bb1830 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -45,7 +45,8 @@
int c400_blk_cnt; \
int c400_host_buf; \
int io_width; \
- int pdma_residual
+ int pdma_residual; \
+ int board
#define NCR5380_dma_xfer_len generic_NCR5380_dma_xfer_len
#define NCR5380_dma_recv_setup generic_NCR5380_pread
@@ -316,6 +317,7 @@ static int generic_NCR5380_init_one(struct
scsi_host_template *tpnt,
}
hostdata = shost_priv(instance);
+ hostdata->board = board;
hostdata->io = iomem;
hostdata->region_size = region_size;
@@ -644,7 +646,12 @@ static int generic_NCR5380_dma_xfer_len(struct
NCR5380_hostdata *hostdata,
/* 53C400 datasheet: non-modulo-128-byte transfers should use PIO */
if (transfersize % 128)
- transfersize = 0;
+ return 0;
+
+ /* Limit PDMA send to 512 B to avoid random corruption on DTC3181E */
+ if (hostdata->board == BOARD_DTC3181E &&
+ cmd->sc_data_direction == DMA_TO_DEVICE)
+ transfersize = min(cmd->SCp.this_residual, 512);
return min(transfersize, DMA_MAX_SIZE);
}
--
2.13.0
