On Monday, November 26, 2012 02:24:09 PM Toshi Kani wrote: > On Mon, 2012-11-26 at 14:09 -0700, Toshi Kani wrote: > > On Mon, 2012-11-26 at 21:44 +0100, Rafael J. Wysocki wrote: > > > On Monday, November 26, 2012 12:06:39 PM Toshi Kani wrote: > > > > On Sat, 2012-11-24 at 23:37 +0100, Rafael J. Wysocki wrote: > > > > > On Saturday, November 24, 2012 11:01:56 PM Rafael J. Wysocki wrote: > > > > > > On Thursday, November 08, 2012 01:23:44 PM Toshi Kani wrote: > > > > > > > Added a new .sys_notify interface, which allows ACPI drivers to > > > > > > > register their system-level (ex. hotplug) notify handlers through > > > > > > > their acpi_driver table. This removes redundant ACPI namespace > > > > > > > walks from ACPI drivers for faster booting. > > > > > > > > > > > > > > The global notify handler acpi_bus_notify() is called for all > > > > > > > system-level ACPI notifications, which then calls an appropriate > > > > > > > driver's handler if any. ACPI drivers no longer need to register > > > > > > > or unregister driver's handler to each ACPI device object. It also > > > > > > > supports dynamic ACPI namespace with LoadTable & Unload opcode > > > > > > > without any modification in ACPI drivers. > > > > > > > > > > > > > > Added a common system notify handler acpi_bus_sys_notify(), which > > > > > > > allows ACPI drivers to set it to .sys_notify when this function is > > > > > > > fully implemented. > > > > > > > > > > > > I don't really understand this. > > > > > > > > > > > > > It removes functional conflict between driver's > > > > > > > notify handler and the global notify handler acpi_bus_notify(). > > > > > > > > > > > > > > Note that the changes maintain backward compatibility for ACPI > > > > > > > drivers. Any drivers registered their hotplug handler through the > > > > > > > existing interfaces, such as acpi_install_notify_handler() and > > > > > > > register_acpi_bus_notifier(), will continue to work as before. > > > > > > > > > > > > I really wouldn't like to add new callbacks to struct acpi_device_ops, because > > > > > > I'd like that whole thing to go away entirely eventually, along with struct > > > > > > acpi_driver. > > > > > > > > > > > > Moreover, in this particular case, it really is not useful to have to define > > > > > > a struct acpi_driver so that one can register for receiving system > > > > > > notifications from ACPI. It would be really nice if non-ACPI drivers, such > > > > > > as PCI or platform, could do that too. > > > > > > > > > > Which they do by using acpi_install_notify_handler() directly. > > > > > > > > By using acpi_install_notify_handler(), each driver needs to walk > > > > through the entire ACPI namespace to find its associated ACPI devices > > > > and call it to register one by one. I think this is more work for > > > > non-ACPI drivers than defining acpi_driver. > > > > > > I'm not really sure what you mean. The drivers in question already know > > > what the relevant ACPI device nodes are (because they need them anyway > > > for other purposes), so they don't need to look for them specifically and > > > acpi_install_notify_handler() doesn't do any namespace walking. So what > > > you said above simply doesn't make sense from this viewpoint. > > > > Yes, if drivers already know the relevant ACPI devices, then walking the > > ACPI namespace is not necessary. I was referring the case like > > processor_driver.c, acpi_memhotplug.c, and container.c in my statement. > > BTW, when an ACPI device is marked as non-present, which is the case > before hot-add, we do not create an acpi_device object and therefore do > not bind it with a driver. This is why these drivers walk the ACPI > namespace and install their notify handlers regardless of device status. So maybe we should create struct acpi_device objects in that case too? Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
