Messages in this thread | | | Date | Tue, 01 Apr 2008 13:06:18 -0700 | From | David Brownell <> | Subject | Re: 2.6.25-rc6 hangs at resume after suspend to RAM on Mac mini Core Duo |
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> git-bisect revealed this: > > $ git bisect good > e82cc1288fa57857c6af8c57f3d07096d4bcd9d9 is first bad commit > commit e82cc1288fa57857c6af8c57f3d07096d4bcd9d9 > Author: David Brownell <david-b@pacbell.net> > Date: Fri Mar 7 13:49:42 2008 -0800 > > USB: fix ehci unlink regressions
Most curious. Based on what I read earlier, I was wondering about the handling of the unlink watchdog during a known-dodgey path.
Specifically:
> The recent EHCI driver update to split the IAA watchdog timer out from > the other timers made several things work better, but not everything; > and it created a couple new issues in bugzilla. Ergo this patch: > > - Handle a should-be-rare SMP race between the watchdog firing > and (very late) IAA interrupts; > > - Remove a shouldn't-have-been-added WARN_ON() test; > > - Guard against one observed OOPS; > > - If this watchdog fires during clean HC shutdown, it should act > as a NOP instead of interfering with the shutdown sequence;
This "fires during a clean shutdown" path. If there's any way this patch would affect resume handling, that's where I'd expect it to kick in. Virtually nothing else *could* cause problems there.
If you'd like to experiment, modify the "if (...)" at the top of the ehci_iaa_watchdog() function and make it just check to see if there's an entry being reclaimed ... comment out the HC_IS_RUNNING() check.
> - Guard against silicon errata hypothesized by some vendors: > * IAA status latch broken, but IAAD cleared OK; > * IAAD wasn't cleared when IAA status got reported;
FWIW the former has been confirmed as existing on some current AMD/ATI chipsets (SB600 and SB700 are the numbers that come to mind).
> The WARN_ON is in bugzilla as 10168; the OOPS as 10078; these are > both regressions. > > Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> > Tested-by: Gordon Farquharson <gordonfarquharson@gmail.com> > Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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