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Documentation / scsi / qlogicfas.txt




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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:04 EST.

1	
2	This driver supports the Qlogic FASXXX family of chips.  This driver
3	only works with the ISA, VLB, and PCMCIA versions of the Qlogic
4	FastSCSI!  cards as well as any other card based on the FASXX chip
5	(including the Control Concepts SCSI/IDE/SIO/PIO/FDC cards).
6	
7	This driver does NOT support the PCI version.  Support for these PCI
8	Qlogic boards:
9	
10		* IQ-PCI
11		* IQ-PCI-10
12		* IQ-PCI-D
13	
14	is provided by the qla1280 driver.
15	
16	Nor does it support the PCI-Basic, which is supported by the
17	'am53c974' driver.
18	
19	PCMCIA SUPPORT
20	
21	This currently only works if the card is enabled first from DOS.  This
22	means you will have to load your socket and card services, and
23	QL41DOS.SYS and QL40ENBL.SYS.  These are a minimum, but loading the
24	rest of the modules won't interfere with the operation.  The next
25	thing to do is load the kernel without resetting the hardware, which
26	can be a simple ctrl-alt-delete with a boot floppy, or by using
27	loadlin with the kernel image accessible from DOS.  If you are using
28	the Linux PCMCIA driver, you will have to adjust it or otherwise stop
29	it from configuring the card.
30	
31	I am working with the PCMCIA group to make it more flexible, but that
32	may take a while.
33	
34	ALL CARDS
35	
36	The top of the qlogic.c file has a number of defines that controls
37	configuration.  As shipped, it provides a balance between speed and
38	function.  If there are any problems, try setting SLOW_CABLE to 1, and
39	then try changing USE_IRQ and TURBO_PDMA to zero.  If you are familiar
40	with SCSI, there are other settings which can tune the bus.
41	
42	It may be a good idea to enable RESET_AT_START, especially if the
43	devices may not have been just powered up, or if you are restarting
44	after a crash, since they may be busy trying to complete the last
45	command or something.  It comes up faster if this is set to zero, and
46	if you have reliable hardware and connections it may be more useful to
47	not reset things.
48	
49	SOME TROUBLESHOOTING TIPS
50	
51	Make sure it works properly under DOS.  You should also do an initial FDISK
52	on a new drive if you want partitions.
53	
54	Don't enable all the speedups first.  If anything is wrong, they will make
55	any problem worse.
56	
57	IMPORTANT
58	
59	The best way to test if your cables, termination, etc. are good is to
60	copy a very big file (e.g. a doublespace container file, or a very
61	large executable or archive).  It should be at least 5 megabytes, but
62	you can do multiple tests on smaller files.  Then do a COMP to verify
63	that the file copied properly.  (Turn off all caching when doing these
64	tests, otherwise you will test your RAM and not the files).  Then do
65	10 COMPs, comparing the same file on the SCSI hard drive, i.e. "COMP
66	realbig.doc realbig.doc".  Then do it after the computer gets warm.
67	
68	I noticed my system which seems to work 100% would fail this test if
69	the computer was left on for a few hours.  It was worse with longer
70	cables, and more devices on the SCSI bus.  What seems to happen is
71	that it gets a false ACK causing an extra byte to be inserted into the
72	stream (and this is not detected).  This can be caused by bad
73	termination (the ACK can be reflected), or by noise when the chips
74	work less well because of the heat, or when cables get too long for
75	the speed.
76	
77	Remember, if it doesn't work under DOS, it probably won't work under
78	Linux.
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