From: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx> 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 <fthain@xxxxxxxxxxxxxxxxxxx> --- 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 9f18082415c4..b1e0a08e49c1 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
