1 files changed, 87 insertions, 0 deletions
diff --git a/Documentation/scsi/qlogicfas.rst b/Documentation/scsi/qlogicfas.rst
new file mode 100644
index 000000000000..b17f1b3676c3
--- /dev/null
+++ b/Documentation/scsi/qlogicfas.rst
@@ -0,0 +1,87 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================================
+Qlogic FASXXX Family Driver Notes
+=================================
+
+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.