From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- Documentation/scsi/dtc3x80.txt | 43 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 Documentation/scsi/dtc3x80.txt (limited to 'Documentation/scsi/dtc3x80.txt') diff --git a/Documentation/scsi/dtc3x80.txt b/Documentation/scsi/dtc3x80.txt new file mode 100644 index 00000000000..e8ae6230ab3 --- /dev/null +++ b/Documentation/scsi/dtc3x80.txt @@ -0,0 +1,43 @@ +README file for the Linux DTC3180/3280 scsi driver. +by Ray Van Tassle (rayvt@comm.mot.com) March 1996 +Based on the generic & core NCR5380 code by Drew Eckhard + +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 +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. + +The driver detects the possible memory addresses (jumper selectable): + CC00, DC00, C800, and D800 +The possible IRQ's (jumper selectable) are: + IRQ 10, 11, 12, 15 +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. +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. -- cgit v1.2.3