aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/scsi/qlogicfas.txt
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/scsi/qlogicfas.txt
Linux-2.6.12-rc2v2.6.12-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!
Diffstat (limited to 'Documentation/scsi/qlogicfas.txt')
-rw-r--r--Documentation/scsi/qlogicfas.txt79
1 files changed, 79 insertions, 0 deletions
diff --git a/Documentation/scsi/qlogicfas.txt b/Documentation/scsi/qlogicfas.txt
new file mode 100644
index 000000000000..398f99168077
--- /dev/null
+++ b/Documentation/scsi/qlogicfas.txt
@@ -0,0 +1,79 @@
1
2This driver supports the Qlogic FASXXX family of chips. This driver
3only works with the ISA, VLB, and PCMCIA versions of the Qlogic
4FastSCSI! cards as well as any other card based on the FASXX chip
5(including the Control Concepts SCSI/IDE/SIO/PIO/FDC cards).
6
7This driver does NOT support the PCI version. Support for these PCI
8Qlogic boards:
9
10 * IQ-PCI
11 * IQ-PCI-10
12 * IQ-PCI-D
13
14is provided by the qlogicisp.c driver. Check README.qlogicisp for
15details.
16
17Nor does it support the PCI-Basic, which is supported by the
18'am53c974' driver.
19
20PCMCIA SUPPORT
21
22This currently only works if the card is enabled first from DOS. This
23means you will have to load your socket and card services, and
24QL41DOS.SYS and QL40ENBL.SYS. These are a minimum, but loading the
25rest of the modules won't interfere with the operation. The next
26thing to do is load the kernel without resetting the hardware, which
27can be a simple ctrl-alt-delete with a boot floppy, or by using
28loadlin with the kernel image accessible from DOS. If you are using
29the Linux PCMCIA driver, you will have to adjust it or otherwise stop
30it from configuring the card.
31
32I am working with the PCMCIA group to make it more flexible, but that
33may take a while.
34
35ALL CARDS
36
37The top of the qlogic.c file has a number of defines that controls
38configuration. As shipped, it provides a balance between speed and
39function. If there are any problems, try setting SLOW_CABLE to 1, and
40then try changing USE_IRQ and TURBO_PDMA to zero. If you are familiar
41with SCSI, there are other settings which can tune the bus.
42
43It may be a good idea to enable RESET_AT_START, especially if the
44devices may not have been just powered up, or if you are restarting
45after a crash, since they may be busy trying to complete the last
46command or something. It comes up faster if this is set to zero, and
47if you have reliable hardware and connections it may be more useful to
48not reset things.
49
50SOME TROUBLESHOOTING TIPS
51
52Make sure it works properly under DOS. You should also do an initial FDISK
53on a new drive if you want partitions.
54
55Don't enable all the speedups first. If anything is wrong, they will make
56any problem worse.
57
58IMPORTANT
59
60The best way to test if your cables, termination, etc. are good is to
61copy a very big file (e.g. a doublespace container file, or a very
62large executable or archive). It should be at least 5 megabytes, but
63you can do multiple tests on smaller files. Then do a COMP to verify
64that the file copied properly. (Turn off all caching when doing these
65tests, otherwise you will test your RAM and not the files). Then do
6610 COMPs, comparing the same file on the SCSI hard drive, i.e. "COMP
67realbig.doc realbig.doc". Then do it after the computer gets warm.
68
69I noticed my system which seems to work 100% would fail this test if
70the computer was left on for a few hours. It was worse with longer
71cables, and more devices on the SCSI bus. What seems to happen is
72that it gets a false ACK causing an extra byte to be inserted into the
73stream (and this is not detected). This can be caused by bad
74termination (the ACK can be reflected), or by noise when the chips
75work less well because of the heat, or when cables get too long for
76the speed.
77
78Remember, if it doesn't work under DOS, it probably won't work under
79Linux.