From 19c9bba94152148523ba0f7ef7cffe3d45656b11 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 29 Apr 1997 21:13:14 +0000 Subject: Import of Linux/MIPS 2.1.36 --- drivers/scsi/README.dtc3x80 | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) (limited to 'drivers/scsi/README.dtc3x80') 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. -- cgit v1.2.3