On Tuesday 24 June 2008 07:37:37 pm Zhao Yakui wrote: > On Tue, 2008-06-24 at 13:52 +0200, Vegard Nossum wrote: > > On 6/24/08, Ingo Molnar <mingo@xxxxxxx> wrote: > > > i havent seen the warning reappear with your fix after thousands of > > > bootups - so i guess we can consider it fixed. > > > > > > Len, please consider the patch below. (it's in tip/out-of-tree) > > > > No, please don't :-) > > > > It fixes your particular case (the acpi_rtc_init() hunk of the patch), > > but the acpi_walk_namespace() part should be changed to a WARN(). But > > that is likely to cause a lot of "spurious" reports, so the other acpi > > drivers should be fixed as well. > In fact this issue is related with the following factors: > a. when acpi is disabled, OS won't initialize the ACPI mutex, which > is accessed by many ACPI interface functions. For example: > acpi_walk_namespace, acpi_install_fixed_event_handler. > b. When acpi is disabled, some drivers will call the ACPI interface > functions. For example: The acpi_walk_namespace is called in > dock_init/bay_init. I think most current uses of acpi_walk_namespace() are indications that the ACPI or PNP core is missing something. In dock_init() and bay_init(), it's used to bind a driver to a device. I think it would be better if we could figure out how to use the usual acpi_bus_register_driver() interface. Actually, it looks like this is already 90% done: acpi_dock_match() does the same thing as is_dock(), so it looks like dock_init() could easily be converted to register as a driver for ACPI_DOCK_HID. bay_init() looks similar, with acpi_bay_match(), is_ejectable_bay(), ACPI_BAY_HID, etc. Other users of acpi_walk_namespace() are often to install notify handlers to deal with add/remove events. I think these are telling us that we need to implement the "TBD: Handle device insertion/removal" pieces in acpi_bus_check_device(). > The acpi_install_fixed_event_handler is called in > the acpi_rtc_init. Yes (via rtc_wake_setup()). I think this should be moved into the RTC driver itself. I have some ideas on how to do this; I'll post a patch in a few days. But for 2.6.26, I think the minimal fix of checking acpi_disabled in acpi_rtc_init() is better. Bjorn -- 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
