On Tuesday, July 15, 2014 11:07:10 AM Lv Zheng wrote: > This patchset enables the ideal GPE handling model. The ideal GPE handling > model should be able to handle the following cases: > > 1. When upper layers (the users of the driver) submit requests to the > drivers, it means they care about the underlying hardware. For this > case, acpi_enable_gpe() should be invoked. When the reference count > is increased from 0 to 1, driver enables the hardware IRQ. And > acpi_disable_gpe() is used as the reversal when the users have > completed the submitted requests. > 2. Driver may temporarily disables the IRQ and wants to re-enable it > later, this case is normally used in order to prevent IRQ storm. > When a driver cannot fully solve the condition that triggered the IRQ > in the IRQ context, in order not to trigger IRQ storm, driver has to > disable IRQ and re-enables it in the deferred execution environment > - which should be in a task context. The acpi_set_gpe() API should be > used exactly for this purpose. > > The reason why this model hasn't been enabled for the current Linux ACPI > drivers is: > In ACPICA, the same GPE lock is held while invoking the GPE handler > callback, it's thus impossible to invoke GPE APIs in the GPE handler > because the APIs require to hold the GPE lock. The recursive locking > leads to dead locks. This is a simple design defect, callbacks should > always be invoked in a lockless environment, normally in Linux, this is > achieved by RCU locking, and in ACPICA, we achieve this using reference > counting. > > After fixing the above bug and doing necessary cleanups in the ACPICA GPE > handling code, we now can enable this ideal GPE handling model for the EC > driver to implement "commands flushing" and "storm prevention" (the EC > driver enabling is not included in this patchset). How this patch series is related to upstream ACPICA? Is the design fixed already upstream? > The refined patches are passed the runtime/suspend tests carried out on the > following platforms with EC driver enhanced: > "Dell Inspiron Mini 1010" - i386 kernel > "Dell Latitude 6430u" - x86_64 kernel > > Lv Zheng (9): > ACPICA: Events: Reduce indent divergences of events files. > ACPICA: Events: Fix an issue that GPE APIs cannot be invoked in > atomic context. > ACPICA: Events: Fix an issue that GPE APIs cannot be invoked in > deferred handlers. > ACPICA: Events: Introduce acpi_set_gpe()/acpi_finish_gpe() to reduce > divergences. > ACPICA: Events: Fix an issue that acpi_set_gpe() cannot > unconditionally enable GPEs. > ACPICA: Events: Fix an issue that status of GPEs are unexpectedly > cleared. > ACPICA: Events: Fix an issue that originally_enabled check is not > paired. > ACPICA: Events: Add a flag to disable internal auto GPE clearing. > ACPI: Update interrupt handler to honor new ACPI_REENABLE_GPE bit. > > drivers/acpi/acpica/acevents.h | 1 + > drivers/acpi/acpica/aclocal.h | 5 +- > drivers/acpi/acpica/evgpe.c | 136 +++++++++++++++++++++------------------- > drivers/acpi/acpica/evxface.c | 41 ++++++++---- > drivers/acpi/acpica/evxfgpe.c | 105 +++++++++++++++++++++++++++++++ > drivers/acpi/osl.c | 2 +- > include/acpi/actypes.h | 16 ++--- > 7 files changed, 219 insertions(+), 87 deletions(-) > > -- 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
