ACPI: Enhance /sys/firmware/interrupts to allow enable/disable/clear …

…from user-space Allow users to enable/disable/clear a specific & valid GPE/Fixed Event in user space. This is useful for debugging, especially for some interrupt storm issues. All wakeup GPEs are disabled and they can not be enabled at runtime, and we mark them as invalid. All GPEs that don't have a _Lxx/_Exx method are marked as invalid. All Fixed Events that don't have an event handler are marked as invalid and they can't be enabled until an event handler is registered. Signed-off-by: Zhang Rui <[email protected]> Signed-off-by: Ling Ming <[email protected]> Signed-off-by: Len Brown <[email protected]> Signed-off-by: Andi Kleen <[email protected]>
redpig · Jul 16, 2008 · 71b58cb · 71b58cb
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commit 71b58cb
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diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi
@@ -29,46 +29,46 @@ Description:
 
 		$ cd /sys/firmware/acpi/interrupts
 		$ grep . *
-		error:0
-		ff_gbl_lock:0
-		ff_pmtimer:0
-		ff_pwr_btn:0
-		ff_rt_clk:0
-		ff_slp_btn:0
-		gpe00:0
-		gpe01:0
-		gpe02:0
-		gpe03:0
-		gpe04:0
-		gpe05:0
-		gpe06:0
-		gpe07:0
-		gpe08:0
-		gpe09:174
-		gpe0A:0
-		gpe0B:0
-		gpe0C:0
-		gpe0D:0
-		gpe0E:0
-		gpe0F:0
-		gpe10:0
-		gpe11:60
-		gpe12:0
-		gpe13:0
-		gpe14:0
-		gpe15:0
-		gpe16:0
-		gpe17:0
-		gpe18:0
-		gpe19:7
-		gpe1A:0
-		gpe1B:0
-		gpe1C:0
-		gpe1D:0
-		gpe1E:0
-		gpe1F:0
-		gpe_all:241
-		sci:241
+		error:	     0
+		ff_gbl_lock:	   0   enable
+		ff_pmtimer:	  0  invalid
+		ff_pwr_btn:	  0   enable
+		ff_rt_clk:	 2  disable
+		ff_slp_btn:	  0  invalid
+		gpe00:	     0	invalid
+		gpe01:	     0	 enable
+		gpe02:	   108	 enable
+		gpe03:	     0	invalid
+		gpe04:	     0	invalid
+		gpe05:	     0	invalid
+		gpe06:	     0	 enable
+		gpe07:	     0	 enable
+		gpe08:	     0	invalid
+		gpe09:	     0	invalid
+		gpe0A:	     0	invalid
+		gpe0B:	     0	invalid
+		gpe0C:	     0	invalid
+		gpe0D:	     0	invalid
+		gpe0E:	     0	invalid
+		gpe0F:	     0	invalid
+		gpe10:	     0	invalid
+		gpe11:	     0	invalid
+		gpe12:	     0	invalid
+		gpe13:	     0	invalid
+		gpe14:	     0	invalid
+		gpe15:	     0	invalid
+		gpe16:	     0	invalid
+		gpe17:	  1084	 enable
+		gpe18:	     0	 enable
+		gpe19:	     0	invalid
+		gpe1A:	     0	invalid
+		gpe1B:	     0	invalid
+		gpe1C:	     0	invalid
+		gpe1D:	     0	invalid
+		gpe1E:	     0	invalid
+		gpe1F:	     0	invalid
+		gpe_all:    1192
+		sci:	1194
 
 		sci - The total number of times the ACPI SCI
 		has claimed an interrupt.
@@ -89,6 +89,13 @@ Description:
 
 		error - an interrupt that can't be accounted for above.
 
+		invalid: it's either a wakeup GPE or a GPE/Fixed Event that
+			doesn't have an event handler.
+
+		disable: the GPE/Fixed Event is valid but disabled.
+
+		enable: the GPE/Fixed Event is valid and enabled.
+
 		Root has permission to clear any of these counters.  Eg.
 		# echo 0 > gpe11
 
@@ -97,3 +104,43 @@ Description:
 
 		None of these counters has an effect on the function
 		of the system, they are simply statistics.
+
+		Besides this, user can also write specific strings to these files
+		to enable/disable/clear ACPI interrupts in user space, which can be
+		used to debug some ACPI interrupt storm issues.
+
+		Note that only writting to VALID GPE/Fixed Event is allowed,
+		i.e. user can only change the status of runtime GPE and
+		Fixed Event with event handler installed.
+
+		Let's take power button fixed event for example, please kill acpid
+		and other user space applications so that the machine won't shutdown
+		when pressing the power button.
+		# cat ff_pwr_btn
+		0
+		# press the power button for 3 times;
+		# cat ff_pwr_btn
+		3
+		# echo disable > ff_pwr_btn
+		# cat ff_pwr_btn
+		disable
+		# press the power button for 3 times;
+		# cat ff_pwr_btn
+		disable
+		# echo enable > ff_pwr_btn
+		# cat ff_pwr_btn
+		4
+		/*
+		 * this is because the status bit is set even if the enable bit is cleared,
+		 * and it triggers an ACPI fixed event when the enable bit is set again
+		 */
+		# press the power button for 3 times;
+		# cat ff_pwr_btn
+		7
+		# echo disable > ff_pwr_btn
+		# press the power button for 3 times;
+		# echo clear > ff_pwr_btn	/* clear the status bit */
+		# echo disable > ff_pwr_btn
+		# cat ff_pwr_btn
+		7
+
diff --git a/drivers/acpi/events/evxfevnt.c b/drivers/acpi/events/evxfevnt.c
@@ -472,7 +472,6 @@ acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number, u32 flags)
 }
 
 ACPI_EXPORT_SYMBOL(acpi_clear_gpe)
-#ifdef ACPI_FUTURE_USAGE
 /*******************************************************************************
  *
  * FUNCTION:    acpi_get_event_status
@@ -489,6 +488,7 @@ ACPI_EXPORT_SYMBOL(acpi_clear_gpe)
 acpi_status acpi_get_event_status(u32 event, acpi_event_status * event_status)
 {
 	acpi_status status = AE_OK;
+	u32 value;
 
 	ACPI_FUNCTION_TRACE(acpi_get_event_status);
 
@@ -506,7 +506,20 @@ acpi_status acpi_get_event_status(u32 event, acpi_event_status * event_status)
 
 	status =
 	    acpi_get_register(acpi_gbl_fixed_event_info[event].
-			      status_register_id, event_status);
+			      enable_register_id, &value);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
+
+	*event_status = value;
+
+	status =
+	    acpi_get_register(acpi_gbl_fixed_event_info[event].
+			      status_register_id, &value);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
+
+	if (value)
+		*event_status |= ACPI_EVENT_FLAG_SET;
 
 	return_ACPI_STATUS(status);
 }
@@ -566,7 +579,6 @@ acpi_get_gpe_status(acpi_handle gpe_device,
 }
 
 ACPI_EXPORT_SYMBOL(acpi_get_gpe_status)
-#endif				/*  ACPI_FUTURE_USAGE  */
 /*******************************************************************************
  *
  * FUNCTION:    acpi_install_gpe_block

diff --git a/drivers/acpi/hardware/hwgpe.c b/drivers/acpi/hardware/hwgpe.c
@@ -186,7 +186,6 @@ acpi_status acpi_hw_clear_gpe(struct acpi_gpe_event_info * gpe_event_info)
  *
  ******************************************************************************/
 
-#ifdef ACPI_FUTURE_USAGE
 acpi_status
 acpi_hw_get_gpe_status(struct acpi_gpe_event_info * gpe_event_info,
 		       acpi_event_status * event_status)
@@ -246,7 +245,6 @@ acpi_hw_get_gpe_status(struct acpi_gpe_event_info * gpe_event_info,
       unlock_and_exit:
 	return (status);
 }
-#endif				/*  ACPI_FUTURE_USAGE  */
 
 /******************************************************************************
  *