[ath9k-devel] [RFC] Serialization of writes

[Luis R. Rodriguez <lrodriguez@atheros.com>]

On Wed, Feb 04, 2009 at 01:02:06PM -0800, Chris Kennedy wrote:
> 
> On Feb 4, 2009, at 2:49 PM, W. van den Akker wrote:
> 
> > On Wednesday 04 February 2009, W. van den Akker wrote:
> >> On Wednesday 04 February 2009, Luis R. Rodriguez wrote:
> >>> On Tue, Feb 3, 2009 at 5:12 PM, Luis R. Rodriguez
> >>>
> >>> <lrodriguez@atheros.com> wrote:
> >>>> Some devices requires serialization of writes, this is required
> >>>> for AR5416 and AR9280 PCI devices. This was not implemented in
> >>>> ath9k
> >>>> though. Here's an attempt, but I have no way of testing this as I
> >>>> haven't had issues with my systems or cards. I am not sure if this
> >>>> should fix some of the current issues being reported but it may
> >>>> help.
> >>>>
> >>>> Those who have issues on SMP systems with hostapd locking up --
> >>>> please give this a whirl, let me know if it helps.
> >>>>
> >>>> This has 3 patches in 1 file, the one that counts it the third one
> >>>> but just apply it all together, 'patch -p1 serialize.patch' (
> >>>> for compat-wireless users or testers) or 'git am serialize.patch'
> >>>> for git users.
> >>>>
> >>>> Feedback on results is appreciated.
> >>>>
> >>>> http://www.kernel.org/pub/linux/kernel/people/mcgrof/patches/
> >>>> ath9k/tmp/
> >>>> se rialize.patch
> >>>
> >>> On second thought, this should be pretty useless since because we
> >>> have
> >>> only one tasklet and tasklets are not re-entrant on different CPUs.
> >>> Hm,,,
> >>
> >> I will test this and will report back..
> >>
> >
> > I have updated the git and applied the patch. But hostapd cannot
> > start the
> > adapter to work:
> >
> > xxx:/home/xx# hostapd -dd /etc/hostapd/hostapd.conf
> > Configuration file: /etc/hostapd/hostapd.conf
> > ctrl_interface_group=0
> > Opening raw packet socket for ifindex 1688
> > BSS count 1, BSSID mask ff:ff:ff:ff:ff:ff (0 bits)
> > Failed to set country code
> > wlan0: Unable to setup interface.
> > rmdir[ctrl_interface]: No such file or directory
> >
> > I am using hostapd 0.6.7.
> 
> I'm not sure why this happened on my system, because i have
> two duplicated identical systems and one works without the
> patch without needing this.  The one doing the same thing as
> yours I just put a card in though so I was thinking maybe it was
> something I did, but if yours is doing it too then that's odd.
> On mine, for the time being till I figure it out, I get it to work by
> doing the following (which is odd because I'm basically jump-starting
> udev, but udev should be working and does the second reg set)...
> 
> export COUNTRY=CO
> /sbin/crda
> hostapd -dd /etc/hostapd/hostapd.conf
> 
> For some reason I just have to run crda manually (I have udev script
> setup in proper place),

I've now have heard a few issues with crda udev stuff.
Please test the udev rule by writing a bash script for your /sbin/crda
with something like this:

#!/bin/bash
LOG=/tmp/crda.log
echo $(date) >> $LOG
echo $COUNTRY >> $LOG
echo ------ >> $LOG
/sbin/crda

Please keep in mind the old crda used to put the udev rule into
/etc/udev/rules.d/regulatory.rules -- this can be removed and the
new place is /lib/udev/rules.d/85-regulatory.rules

Note that restarting udev is not required as udev has an inotify for
the daemon on the directories IIRC.

  Luis