On Thu, 2008-09-11 at 21:49 +0200, Oldrich Jedlicka wrote: > On Thursday 04 of September 2008 at 14:18:20, Andi Kleen wrote: > > On Tue, Aug 26, 2008 at 01:57:34PM +0800, Zhao Yakui wrote: > > > Subject: ACPI: Avoid bogus timeout about SMbus check > > > > > > >From : Zhao Yakui <yakui.zhao@xxxxxxxxx> > > > > > > In the function of wait_transaction_complete when the timeout happens, > > > OS will try to check the status of SMbus again. If the status is what OS > > > expected, it will be regarded as the bogus timeout. Otherwise it will be > > > treated as ETIME. > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=10483 > > > > I added it for 2.6.27 thanks (since it seems to be a regression) > > Hi all, > > the problem in bug 10483 isn't solved, unfortunately the patch applied to > 2.6.27 isn't the one I tested. > > The problem I face is that wait_transaction_complete() in sbshc.c doesn't take > at most "timeout" time (=one second), but it rather often takes very long > time to complete on my system (several minutes) - notebook Acer TravelMate > 4502WLMi. > To describe the problem I need to go into wait_event_timeout() macro as used > in wait_transaction_complete(): it first calls the user method > smb_check_done() to check if the loop should end and if not, it waits for at > most "timeout" time. The wait can be woken-up by a wake_up() method and if > so, it remembers the remaining "timeout", repeats the call to user method > smb_check_done() and possibly continues with wait (with the > remaining "timeout"). This is done in a loop. > > Now my problem: the wait_event_timeout() loop takes several minutes instead of > one second (as specified by the parameter "timeout"). The reason for that - as > I think - is this: > > 1. The smb_check_done() method called each loop takes some time to execute, > but this time is not included into the overall timeout. What you said is right. It will take some time to execute the function of smb_check_done. When the ec_read is called in smb_check_done, maybe it will also sleep for some time in ec_read. But this time is not accounted into the overall timeout. Please use the following mechanism to replace the wait_event_timeout. unsigned long delay = jiffies + msecs_to_jiffies(timeout); while (time_before(jiffies, delay)) { if (smb_check_done(hc)) return 0; msleep(1); } > 2. The wait_event_timeout() is woken-up by smbus_alarm() very early each > loop, so the remaining "timeout" gets lower very slow (I think it is so, but > I haven't verified this hypothesis yet). > > So my question is what I shoud do now? If you want to see some logs (and the > original patch), please go to my bug report: > > http://bugzilla.kernel.org/show_bug.cgi?id=10483 > > Thanks. > > Note: I'm building my house after my normal work, so I don't have much time > left, but I will do my best to try whatever you suggest. And sorry for my > english :-) > > Regards, > Oldrich. > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
