Re: [PATCH] ehci errors during cpu frequency changes
David Brownell <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Thursday 12 April 2007 8:51 am, [email protected] wrote: > Hayes, Stuart wrote: > > EHCI controllers that don't cache enough microframes can get MMF > > errors when CPU frequency changes occur between the start and > > completion of split interrupt transactions, due to delays in reading > > main memory (caused by CPU cache snoop delays). > > > > This patch adds a cpufreq notifier to the EHCI driver that will > > inactivate split interrupt transactions during frequency transitions. > > It was tested on Intel ICH7 and Serverworks/Broadcom HT1000 EHCI > > controllers. > > > > Signed-off-by: Stuart Hayes <[email protected]> > > > Does the lack of response mean that this patch won't be accepted? No. I've been running it on my laptop for a few days now -- albeit without lowspeed devices -- and was expecting to take the next step (final review of the code, before forwarding it to Greg) soon. Maybe today even. I was just thinking about this yesterday, in fact. This one seems easier to approve than the one adding support for curious byte ordering in various vendors' EHCI silicon. ;) - Dave > Is there anything I could do to make it more acceptable? There's > definitely an issue that this addresses... if this patch isn't good for > some reason I'll be happy to try another approach. The only other thing > I can think of--other than setting the I bit--is to unlink all of the > split interrupt QHs during CPU frequency transitions. > > Or... I could add a kernel parameter so that this patch wouldn't be > enabled by default, so that only users who are seeing the problem could > turn it on... that way this could get some wider testing without risk of > everybody's USB subsystems failing mysteriously... > > Thanks > Stuart > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel