Ultrix tape job is unkillable!

[The Beach Bum]

In article <1988Dec18.023931.28730 at utzoo.uucp> henry at utzoo.uucp (Henry Spencer) writes:
>Many, many device drivers unfortunately don't observe a general rule of
>robustness:  unless there is legitimate reason for a device operation to
>take an unbounded time to complete (e.g. a read from a terminal), drivers
>should *never* sleep waiting for a device without setting a timeout.

Or as a minimum, provide a means of awakening a wedged driver.  Perhaps
by using a single event and checking for error conditions or completion
prior to sleeping or continuing.

>This applies to *all* devices, since hardware failures should be handled
>more gracefully than by just hanging, but devices that can wander off into
>limbo due to human intervention are particularly important cases.

And as a suggestion - the inclusion of an ioctl to RESET the device
has proven most helpful with a certain vendors hardware which is highly
prone to extreme flakyness.
-- 
John F. Haugh II                        +-Quote of the Week:-------------------
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