diff options
| author | Ondrej Zary <linux@rainbow-software.org> | 2017-07-03 09:59:06 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-08-07 20:04:00 +0200 |
| commit | facfc963ae92f8f47f79905927da024ae779a2c1 (patch) | |
| tree | 3ab67da1df7ecba2fdd6e8ca2f1a9ce69f10c824 | |
| parent | scsi: g_NCR5380: Re-work PDMA loops (diff) | |
| download | linux-facfc963ae92f8f47f79905927da024ae779a2c1.tar.xz linux-facfc963ae92f8f47f79905927da024ae779a2c1.zip | |
scsi: g_NCR5380: Two DTC436 PDMA workarounds
Limit PDMA send to 512 B to avoid data corruption on DTC3181E. 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.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/scsi/g_NCR5380.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c index 7d1d75d60029..b4da4811b7a1 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_precv @@ -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; @@ -492,6 +494,8 @@ static void wait_for_53c80_access(struct NCR5380_hostdata *hostdata) int count = 10000; do { + if (hostdata->board == BOARD_DTC3181E) + udelay(4); /* DTC436 chip hangs without this */ if (NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG) return; } while (--count > 0); @@ -665,7 +669,12 @@ 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); } |