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From: speck@CIT-VAX.ARPA
Newsgroups: net.unix-wizards
Subject: Clarification of device driver subtleties
Message-ID: <375@sri-arpa.UUCP>
Date: Tue, 24-Jul-84 16:43:00 EDT
Article-I.D.: sri-arpa.375
Posted: Tue Jul 24 16:43:00 1984
Date-Received: Fri, 27-Jul-84 08:19:45 EDT
Lines: 15

From:  Don Speck <speck@CIT-VAX.ARPA>

    Before I get any more letters misinterpreting my question, let me
clarify:  nowhere did I mention ANYTHING about calling sleep() from an
interrupt routine!  As you can see in my letter, I call sleep() at ipl
0x14 from rlpwrite(), the write routine for my driver.	Please don't
tell me that it can't work, because a lot of 4.2bsd drivers do it; look
at lpoutput() in /sys/vaxuba/lp.c.
    Perhaps I confused everybody by using the term "interrupt level"
when I should say "processor priority raised to ipl 0x14 to temporarily
lock out interrupts during a critical section".  So let me rephrase the
question:
    Does sleep() do anything strange when called with processor priority
at 0x14, and can signals such as SIGINT/SIGQUIT interrupt such a sleep?
						Don Speck