kern/153205: [ahci] PIONEER DVD-RW: timeout with ahci(4), OK with ata(4) + ATA_CAM

[Dmytro Pryanyshnikov]

The following reply was made to PR kern/153205; it has been noted by GNATS.

From: Dmytro Pryanyshnikov <lynx.ripe at gmail.com>
To: Alexander Motin <mav at freebsd.org>
Cc: bug-followup at freebsd.org
Subject: Re: kern/153205: [ahci] PIONEER DVD-RW: timeout with ahci(4), OK with
 ata(4) + ATA_CAM
Date: Fri, 29 Apr 2011 21:06:30 +0300

 Hello!
 
 2011/4/28 Alexander Motin <mav at freebsd.org>:
 > Hi.
 >
 > As I can see from dmesg, controller reports that command is completed,
 > but driver either haven't received interrupt or mishandled it.
 >
 > Just an idea, could you try to disable MSI interrupts for the controller
 > by setting hint.ahci.0.msi=0 in /boot/loader.conf?
 
   I've made an investigation using the same kernel config as in
 original submission:
 
 http://sites.google.com/site/lynxripe/freebsd/pr/20101216-ahci/lynx
 
 but with more recent RELENG_8 sources (as of 2011-03-07). So, without
 disabling MSI, problem is the same as originally described (timeout +
 no cd0 when using ahci instead of ata with the Intel ICH7 AHCI SATA
 controller):
 
 http://sites.google.com/site/lynxripe/freebsd/pr/153205/110429/dmesg.txt
 
 Setting hint.ahci.0.msi=0 _almost_ cures the problem: cd0 works, and
 verbose boot logs most often look like this:
 
 http://sites.google.com/site/lynxripe/freebsd/pr/153205/110429/dmesg-nomsi.txt
 
 However, sometimes (I've seen it 2 times out of 6 reboots) vestiges of
 the problem still appear in the form of non-fatal timeout:
 
 http://sites.google.com/site/lynxripe/freebsd/pr/153205/110429/dmesg-nomsi2.txt
 http://sites.google.com/site/lynxripe/freebsd/pr/153205/110429/dmesg-nomsi3.txt
 
 OTOH, ata(4)+ATA_CAM works with MSI enabled for this controller
 (hint.atapci.1.msi=1) just fine:
 
 http://sites.google.com/site/lynxripe/freebsd/pr/153205/110429/dmesg-ata-msi.txt
 
 
 >
 > --
 > Alexander Motin
 >
 
 
 
 -- 
 Sincerely, Dmytro