Documentation/scsi/qlogicfas.txt - third_party/linux - Git at Google


 This driver supports the Qlogic FASXXX family of chips.  This driver
 only works with the ISA, VLB, and PCMCIA versions of the Qlogic
 FastSCSI!  cards as well as any other card based on the FASXX chip
 (including the Control Concepts SCSI/IDE/SIO/PIO/FDC cards).

 This driver does NOT support the PCI version.  Support for these PCI
 Qlogic boards:

 	* IQ-PCI
 	* IQ-PCI-10
 	* IQ-PCI-D

 is provided by the qla1280 driver.

 Nor does it support the PCI-Basic, which is supported by the
 'am53c974' driver.

 PCMCIA SUPPORT

 This currently only works if the card is enabled first from DOS.  This
 means you will have to load your socket and card services, and
 QL41DOS.SYS and QL40ENBL.SYS.  These are a minimum, but loading the
 rest of the modules won't interfere with the operation.  The next
 thing to do is load the kernel without resetting the hardware, which
 can be a simple ctrl-alt-delete with a boot floppy, or by using
 loadlin with the kernel image accessible from DOS.  If you are using
 the Linux PCMCIA driver, you will have to adjust it or otherwise stop
 it from configuring the card.

 I am working with the PCMCIA group to make it more flexible, but that
 may take a while.

 ALL CARDS

 The top of the qlogic.c file has a number of defines that controls
 configuration.  As shipped, it provides a balance between speed and
 function.  If there are any problems, try setting SLOW_CABLE to 1, and
 then try changing USE_IRQ and TURBO_PDMA to zero.  If you are familiar
 with SCSI, there are other settings which can tune the bus.

 It may be a good idea to enable RESET_AT_START, especially if the
 devices may not have been just powered up, or if you are restarting
 after a crash, since they may be busy trying to complete the last
 command or something.  It comes up faster if this is set to zero, and
 if you have reliable hardware and connections it may be more useful to
 not reset things.

 SOME TROUBLESHOOTING TIPS

 Make sure it works properly under DOS.  You should also do an initial FDISK
 on a new drive if you want partitions.

 Don't enable all the speedups first.  If anything is wrong, they will make
 any problem worse.

 IMPORTANT

 The best way to test if your cables, termination, etc. are good is to
 copy a very big file (e.g. a doublespace container file, or a very
 large executable or archive).  It should be at least 5 megabytes, but
 you can do multiple tests on smaller files.  Then do a COMP to verify
 that the file copied properly.  (Turn off all caching when doing these
 tests, otherwise you will test your RAM and not the files).  Then do
 10 COMPs, comparing the same file on the SCSI hard drive, i.e. "COMP
 realbig.doc realbig.doc".  Then do it after the computer gets warm.

 I noticed my system which seems to work 100% would fail this test if
 the computer was left on for a few hours.  It was worse with longer
 cables, and more devices on the SCSI bus.  What seems to happen is
 that it gets a false ACK causing an extra byte to be inserted into the
 stream (and this is not detected).  This can be caused by bad
 termination (the ACK can be reflected), or by noise when the chips
 work less well because of the heat, or when cables get too long for
 the speed.

 Remember, if it doesn't work under DOS, it probably won't work under
 Linux.

	This driver supports the Qlogic FASXXX family of chips. This driver
	only works with the ISA, VLB, and PCMCIA versions of the Qlogic
	FastSCSI! cards as well as any other card based on the FASXX chip
	(including the Control Concepts SCSI/IDE/SIO/PIO/FDC cards).

	This driver does NOT support the PCI version. Support for these PCI
	Qlogic boards:

	* IQ-PCI
	* IQ-PCI-10
	* IQ-PCI-D

	is provided by the qla1280 driver.

	Nor does it support the PCI-Basic, which is supported by the
	'am53c974' driver.

	PCMCIA SUPPORT

	This currently only works if the card is enabled first from DOS. This
	means you will have to load your socket and card services, and
	QL41DOS.SYS and QL40ENBL.SYS. These are a minimum, but loading the
	rest of the modules won't interfere with the operation. The next
	thing to do is load the kernel without resetting the hardware, which
	can be a simple ctrl-alt-delete with a boot floppy, or by using
	loadlin with the kernel image accessible from DOS. If you are using
	the Linux PCMCIA driver, you will have to adjust it or otherwise stop
	it from configuring the card.

	I am working with the PCMCIA group to make it more flexible, but that
	may take a while.

	ALL CARDS

	The top of the qlogic.c file has a number of defines that controls
	configuration. As shipped, it provides a balance between speed and
	function. If there are any problems, try setting SLOW_CABLE to 1, and
	then try changing USE_IRQ and TURBO_PDMA to zero. If you are familiar
	with SCSI, there are other settings which can tune the bus.

	It may be a good idea to enable RESET_AT_START, especially if the
	devices may not have been just powered up, or if you are restarting
	after a crash, since they may be busy trying to complete the last
	command or something. It comes up faster if this is set to zero, and
	if you have reliable hardware and connections it may be more useful to
	not reset things.

	SOME TROUBLESHOOTING TIPS

	Make sure it works properly under DOS. You should also do an initial FDISK
	on a new drive if you want partitions.

	Don't enable all the speedups first. If anything is wrong, they will make
	any problem worse.

	IMPORTANT

	The best way to test if your cables, termination, etc. are good is to
	copy a very big file (e.g. a doublespace container file, or a very
	large executable or archive). It should be at least 5 megabytes, but
	you can do multiple tests on smaller files. Then do a COMP to verify
	that the file copied properly. (Turn off all caching when doing these
	tests, otherwise you will test your RAM and not the files). Then do
	10 COMPs, comparing the same file on the SCSI hard drive, i.e. "COMP
	realbig.doc realbig.doc". Then do it after the computer gets warm.

	I noticed my system which seems to work 100% would fail this test if
	the computer was left on for a few hours. It was worse with longer
	cables, and more devices on the SCSI bus. What seems to happen is
	that it gets a false ACK causing an extra byte to be inserted into the
	stream (and this is not detected). This can be caused by bad
	termination (the ACK can be reflected), or by noise when the chips
	work less well because of the heat, or when cables get too long for
	the speed.

	Remember, if it doesn't work under DOS, it probably won't work under
	Linux.