On Sun, Dec 06, 2009 at 09:31:12PM -0800, Arjan van de Ven wrote: > On Sun, 6 Dec 2009 18:27:07 -0800 > Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > > > On Sun, Dec 06, 2009 at 05:18:56PM -0800, Arjan van de Ven wrote: > > > On Sun, 6 Dec 2009 14:54:48 -0800 > > > Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > > > > > > > Yes, that's your PS/2 mouse (rather touchpad) and the delay comes > > > > from device reset (needed by some keyboard controllers - I > > > > remember HP -or it and keyboard will be dead at resume). > > > > > > > > > > btw could we do this reset in an async function call (as long as we > > > wait for it to complete before we pull the plug finally) ? > > > > It has to complete before we start shutting down i8042, so there are > > dependencies involved... > > async function calls have 2 methods for synchronization: > > * inside an async function, you can wait for all "earlier" async > functions to complete (async_synchronize_cookie) > * outside an async function, you can wait for all scheduled async > functions to complete (async_synchronize_full) > > so there's two options to use the async code to cut down this time: > > 1) Make both the mouse, keyboard AND the i8042 suspend functions async, > and in the i8042 function the code first synchronizes on all previous > async work > 2) only make the mouse and keyboard suspend async, and just wait for all > async work in i8042 suspend > > I strongly prefer number 1, in terms of getting the best suspend speed. > It means that all other suspend code can run in parallel to the whole > serio/i8042 suspend. > Option two is simpler, but the delay is in the normal, synchronous path, > so other suspend code will not run in parallel. > > The good news is that neither is hard for someone familiar with the > code... > And the bad thing is that violates multiple layers in the kernel. Atkbd driver does not have to be using i8042; neither does psmouse. Althtough they do in 99% of the cases there are other controllers providing the i8042-style ports. Just grep for SERIO_8042 in drivers/input/serio. I do not want to hard-code the i8042-psmouse-atkbd dependency. -- Dmitry -- 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
