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Date: Tue, 11 Jan 2000 16:29:16 -0800 (PST)
From: sam@errno.com
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Subject: i386/16071: ata driver has a race in ata_command
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>Number:         16071
>Category:       i386
>Synopsis:       ata driver has a race in ata_command
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 11 16:30:00 PST 2000
>Closed-Date:
>Last-Modified:
>Originator:     Sam Leffler
>Release:        4.0-CURRENT
>Organization:
>Environment:
FreeBSD melange.errno.com 4.0-CURRENT FreeBSD 4.0-CURRENT #0: Thu Jan  6 23:50:00 GMT 2000     root@melange.errno.com:/home/sam/freebsd/src/sys/compile/MELANGE  i386


>Description:
ata_command (1.39) sends a command before doing a tsleep to wait for the result.
If the device interrupts before tsleep is able to place the process on the sleep
queue then the interrupt will be missed.
>How-To-Repeat:
Boot 4.0-CURRENT under vmware w/ the ata driver configured instead of the
wd driver.  Notice that no IDE devices are recognized; each gets a complaint:

ata_command: timeout waiting for interrupt

A little investigation shows the obvious race that's exasperated by operating
in a pseudo-synchronous environment.
>Fix:
I'll let Soren (sic?) do his own.

>Release-Note:
>Audit-Trail:
>Unformatted:


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