On Sun, 3 Jul 2011 08:58:41 +0200 "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > On Saturday, July 02, 2011, Andrea Righi wrote: > > Implement acpi_os_create_lock() as a C-preprocessor macro to assign > > unique lock_class_key to dynamically allocated locks and suppress wrong > > lockdep warnings. > > > > This fixes: > > https://bugzilla.kernel.org/show_bug.cgi?id=38152 > > > > Reported-by: Borislav Petkov <bp@xxxxxxxxx> > > Signed-off-by: Andrea Righi <andrea@xxxxxxxxxxxxxxx> > > So, how exactly does it work? The spin_lock_init macro stringifies it's argument and uses that as a name for the lock in the debugging. By re-executing spin_lock_init (have not checked if that harms anything, but it should be ok) in the _macro_ the key changes from "lock" for all three locks to the actual argument "&acpi_gbl_global_lock_pending_lock", "&acpi_gbl_gpe_lock" or "&acpi_gbl_hardware_lock". Regards, Flo > > --- > > drivers/acpi/osl.c | 2 +- > > include/acpi/acpiosxf.h | 12 +++++++++++- > > 2 files changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c > > index 52ca964..2a67602 100644 > > --- a/drivers/acpi/osl.c > > +++ b/drivers/acpi/osl.c > > @@ -1336,7 +1336,7 @@ EXPORT_SYMBOL(acpi_resources_are_enforced); > > * Create and initialize a spinlock. > > */ > > acpi_status > > -acpi_os_create_lock(acpi_spinlock *out_handle) > > +__acpi_os_create_lock(acpi_spinlock *out_handle) > > { > > spinlock_t *lock; > > > > diff --git a/include/acpi/acpiosxf.h b/include/acpi/acpiosxf.h > > index a756bc8..4a0385d 100644 > > --- a/include/acpi/acpiosxf.h > > +++ b/include/acpi/acpiosxf.h > > @@ -99,7 +99,17 @@ acpi_os_table_override(struct acpi_table_header *existing_table, > > * Spinlock primitives > > */ > > acpi_status > > -acpi_os_create_lock(acpi_spinlock *out_handle); > > +__acpi_os_create_lock(acpi_spinlock *out_handle); > > + > > +#define acpi_os_create_lock(__handle) \ > > +({ \ > > + acpi_status ret; \ > > + \ > > + ret = __acpi_os_create_lock(__handle); \ > > + if (ret == AE_OK) \ > > + spin_lock_init(*(__handle)); \ > > It seems that spin_lock_init() has already been done on *__handle, right? > > > + ret; \ > > +}) > > > > void acpi_os_delete_lock(acpi_spinlock handle); > > Rafael -- 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
