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authorRalf Baechle <ralf@linux-mips.org>1997-04-29 21:13:14 +0000
committer <ralf@linux-mips.org>1997-04-29 21:13:14 +0000
commit19c9bba94152148523ba0f7ef7cffe3d45656b11 (patch)
tree40b1cb534496a7f1ca0f5c314a523c69f1fee464 /drivers/scsi/README.dtc3x80
parent7206675c40394c78a90e74812bbdbf8cf3cca1be (diff)
Import of Linux/MIPS 2.1.36
Diffstat (limited to 'drivers/scsi/README.dtc3x80')
-rw-r--r--drivers/scsi/README.dtc3x8037
1 files changed, 19 insertions, 18 deletions
diff --git a/drivers/scsi/README.dtc3x80 b/drivers/scsi/README.dtc3x80
index ce5083612..57ecf7951 100644
--- a/drivers/scsi/README.dtc3x80
+++ b/drivers/scsi/README.dtc3x80
@@ -6,15 +6,17 @@ SCSI device driver for the DTC 3180/3280.
Data Technology Corp---a division of Qume.
The 3280 has a standard floppy interface.
+
The 3180 does not. Otherwise, they are identical.
+
The DTC3x80 does not support DMA but it does have Pseudo-DMA which is
supported by the driver.
+
It's DTC406 scsi chip is supposedly compatible with the NCR 53C400.
-It is memory mapped, uses an IRQ, but no dma or io-port. There is
+It is memory mapped, uses an IRQ, but no dma or io-port. There is
internal DMA, between SCSI bus and an on-chip 128-byte buffer. Double
-buffering is done automagically by the chip.
-Data is transferred between the on-chip buffer and CPU/RAM via
-memory moves.
+buffering is done automagically by the chip. Data is transferred
+between the on-chip buffer and CPU/RAM via memory moves.
The driver detects the possible memory addresses (jumper selectable):
CC00, DC00, C800, and D800
@@ -24,21 +26,20 @@ Parity is supported by the chip, but not by this driver.
Information can be obtained from /proc/scsi/dtc3c80/N.
Note on interrupts:
+
The documentation says that it can be set to interrupt whenever the
-on-chip buffer needs CPU attention. I couldn't get this to work.
-So the driver polls for data-ready in the pseudo-DMA transfer routine.
+on-chip buffer needs CPU attention. I couldn't get this to work. So
+the driver polls for data-ready in the pseudo-DMA transfer routine.
The interrupt support routines in the NCR3280.c core modules handle
-scsi disconnect/reconnect, and this (mostly) works.
-However.....
-I have tested it with 4 totally different hard drives (both SCSI-1
-and SCSI-2), and one CDROM drive.
-Interrupts works great for all but one specific hard drive. For this one,
-the driver will eventually hang in the transfer state.
-I have tested with: "dd bs=4k count=2k of=/dev/null if=/dev/sdb". It
-reads ok for a while, then hangs. After beating my head against this for a
-couple of weeks, getting nowhere, I give up.
-So.....This driver does NOT use interrupts, even if you have the card
-jumpered to an IRQ. Probably nobody will ever care.
-Nor will I when the $380 2.5GB IDE drives hit the market in early 1996!
+scsi disconnect/reconnect, and this (mostly) works. However..... I
+have tested it with 4 totally different hard drives (both SCSI-1 and
+SCSI-2), and one CDROM drive. Interrupts works great for all but one
+specific hard drive. For this one, the driver will eventually hang in
+the transfer state. I have tested with: "dd bs=4k count=2k
+of=/dev/null if=/dev/sdb". It reads ok for a while, then hangs.
+After beating my head against this for a couple of weeks, getting
+nowhere, I give up. So.....This driver does NOT use interrupts, even
+if you have the card jumpered to an IRQ. Probably nobody will ever
+care.