Bug 11293

Summary: 2.6.27-rc2: MSI vs. ath5k suspend regression on EeePC
Product: Drivers Reporter: Rafael J. Wysocki (rjw)
Component: network-wirelessAssignee: drivers_network-wireless (drivers_network-wireless)
Status: CLOSED CODE_FIX    
Severity: normal CC: alan-jenkins, bunk, pavel
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.27-rc2 Subsystem:
Regression: Yes Bisected commit-id:
Bug Depends on:    
Bug Blocks: 7216, 11167    
Attachments: Proposed fix

Description Rafael J. Wysocki 2008-08-09 14:44:25 UTC 
Subject    : 2.6.27-rc2: suspend regression on EeePC
Submitter  : Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Date       : 2008-08-06 18:59
References : http://thread.gmane.org/gmane.linux.kernel.kernel-testers/701

This entry is being used for tracking a regression from 2.6.26.  Please don't
close it until the problem is fixed in the mainline.
Comment 1 Alan Jenkins 2008-08-11 08:47:10 UTC 
Created attachment 17179 [details]
Proposed fix

Mainline ath5k doesn't use MSI, but a patch slipped in which enabled it on resume.
Comment 2 John W. Linville 2008-08-14 10:43:23 UTC 
commit 256b152b005e319f985f50f2a910a75ba0def74f
Author: Pavel Roskin <proski@gnu.org>
Date:   Fri Jul 18 12:56:59 2008 -0400

    ath5k: don't enable MSI, we cannot handle it yet
    
    MSI is a nice thing, but we cannot enable it without changing the
    interrupt handler.  If we do it, we break MSI capable hardware,
    specifically AR5006 chipset.
    
    Signed-off-by: Pavel Roskin <proski@gnu.org>
    Acked-by: Nick Kossifidis <mickflemm@gmail.com>
    Cc: stable <stable@kernel.org>
    Signed-off-by: John W. Linville <linville@tuxdriver.com>
Comment 3 Alan Jenkins 2008-08-15 03:18:50 UTC 
Wrong!  Testing confirms this regression is still present in 2.6.27-rc3.  Please re-read my problem description and proposed fix.

256b152b005e319f985f50f2a910a75ba0def74f only touches the probe/remove routines in base.c.  It missed the suspend/resume callbacks in hw.c which disable/re-enable MSI (which I believe is unnecessary anyway as this is done my the pci core).

Credit should go to Michael Karcher, who independently posted a similar patch on ath5k-devel several days before me.
Comment 4 John W. Linville 2008-08-15 06:21:14 UTC 
Ah, sorry.  I'll pick-up that fix in the next round.