[SCSI] wd33c93: Fast SCSI with WD33C93B
Attached are patches, which help to utilize more of the WD33C93B SCSI
controller's capabilities.
1) Added/changed all the necessary code to enable Burst Mode DMA. Only
Single Byte DMA was used before.
2) Added/changed all the necessary code to enable Fast-10 SCSI transfers.
3) The original driver inadvertently used a transfer period of 1000-800ns
(the lowest possible transfer rate) for asynchronous data transfers,
instead of the (configurable) default period intended for this purpose,
if the target responded to a SDTR not with a Reject-message, but with
a zero-SDTR. This issue was fixed.
Moreover, in case of a Reject the driver used the default-period's
initialization-value instead of its (maybe smaller) current value. The
missing assignment was added.
4) The driver's commandline- and proc-file-interface was augmented to
handle the new options properly.
The WD33C93 manual, found at
http://www.datasheet.in/datasheet-html/W/D/3/WD33C93B_WesternDigital.pdf.html,
was very helpful.
Signed-off-by: peter fuerst <post@pfrst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/wd33c93.h b/drivers/scsi/wd33c93.h
index edcb036..61ffb86 100644
--- a/drivers/scsi/wd33c93.h
+++ b/drivers/scsi/wd33c93.h
@@ -155,6 +155,9 @@
#define WD33C93_FS_12_15 OWNID_FS_12
#define WD33C93_FS_16_20 OWNID_FS_16
+ /* pass input-clock explicitely. accepted mhz values are 8-10,12-20 */
+#define WD33C93_FS_MHZ(mhz) (mhz)
+
/* Control register */
#define CTRL_HSP 0x01
#define CTRL_HA 0x02
@@ -253,6 +256,9 @@
uchar sync_stat[8]; /* status of sync negotiation per target */
uchar no_sync; /* bitmask: don't do sync on these targets */
uchar no_dma; /* set this flag to disable DMA */
+ uchar dma_mode; /* DMA Burst Mode or Single Byte DMA */
+ uchar fast; /* set this flag to enable Fast SCSI */
+ struct sx_period sx_table[9]; /* transfer periods for actual DTC-setting */
#ifdef PROC_INTERFACE
uchar proc; /* bitmask: what's in proc output */
#ifdef PROC_STATISTICS