Calling pm-suspend might trigger a recursive lock in it's code path. In function acpi_hw_clear_acpi_status, acpi_os_acquire_lock holds the lock acpi_gbl_hardware_lock before calling acpi_hw_register_write(), then without releasing acpi_gbl_hardware_lock, this function calls acpi_ev_walk_gpe_list, which tries to hold acpi_gbl_gpe_lock and thus might causes possible recursive lock. Following patch fixes this scenario by just releasing acpi_gbl_hardware_lock before calling acpi_ev_walk_gpe_list. Changes since v0(https://lkml.org/lkml/2011/9/21/355): - Fix changelog, thanks to Lin Ming. Signed-off-by: Rakib Mullick <rakib.mullick@xxxxxxxxx> Cc: Lin Ming <ming.m.lin@xxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> --- diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index 55accb7..e3110ac 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -269,6 +269,9 @@ acpi_status acpi_hw_clear_acpi_status(void) status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, ACPI_BITMASK_ALL_FIXED_STATUS); + + acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); + if (ACPI_FAILURE(status)) { goto unlock_and_exit; } @@ -278,7 +281,6 @@ acpi_status acpi_hw_clear_acpi_status(void) status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL); unlock_and_exit: - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); return_ACPI_STATUS(status); } -- 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
