[SCSI] 53c700: Allow setting burst length
This is a patch, which allows not only disabling bursting but to specify
different burst lenghts. This feature is needed to get the 53c700 driver
working for the onboard SCSI controller of SNI RM machines, which only
work reliably with a 4 word burst length.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index 68103e5..88e061d 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -667,12 +667,30 @@
__u8 min_xferp = (hostdata->chip710 ? NCR_710_MIN_XFERP : NCR_700_MIN_XFERP);
if(hostdata->chip710) {
- __u8 burst_disable = hostdata->burst_disable
- ? BURST_DISABLE : 0;
+ __u8 burst_disable = 0;
+ __u8 burst_length = 0;
+
+ switch (hostdata->burst_length) {
+ case 1:
+ burst_length = BURST_LENGTH_1;
+ break;
+ case 2:
+ burst_length = BURST_LENGTH_2;
+ break;
+ case 4:
+ burst_length = BURST_LENGTH_4;
+ break;
+ case 8:
+ burst_length = BURST_LENGTH_8;
+ break;
+ default:
+ burst_disable = BURST_DISABLE;
+ break;
+ }
dcntl_extra = COMPAT_700_MODE;
NCR_700_writeb(dcntl_extra, host, DCNTL_REG);
- NCR_700_writeb(BURST_LENGTH_8 | hostdata->dmode_extra,
+ NCR_700_writeb(burst_length | hostdata->dmode_extra,
host, DMODE_710_REG);
NCR_700_writeb(burst_disable | (hostdata->differential ?
DIFF : 0), host, CTEST7_REG);