Commit 4c237371 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI / EC: Remove old CLEAR_ON_RESUME quirk 

IRQ polling logic has been implemented to drain the post-boot/resume
EC events:

 1. Triggered by the following code, invoked from acpi_ec_enable_event():

	if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
		advance_transaction(ec);

 2. Drained by the following code, invoked after acpi_ec_complete_query():

	if (status & ACPI_EC_FLAG_SCI)
		acpi_ec_submit_query(ec);

This facility is safer than the old CLEAR_ON_RESUME quirk as the
CLEAR_ON_RESUME quirk sends EC query commands unconditionally. The
behavior is apparently not suitable for firmware that requires
QUERY_HANDSHAKE quirk. Though the QUERY_HANDSHAKE quirk isn't used
now because of the improvement done in the EC transaction state
machine (ec_event_clearing=QUERY), it is the proof that we cannot
send EC query command unconditionally.

So it's time to delete the out-dated CLEAR_ON_RESUME quirk to let the
users to try the newer approach.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=191211


Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 566cf877

drivers/acpi/ec.c

+0 −53
Original line number Diff line number Diff line
@@ -188,7 +188,6 @@ EXPORT_SYMBOL(first_ec); 
static bool boot_ec_is_ecdt = false;

static struct workqueue_struct *ec_query_wq;



static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */

static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */

static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
@@ -492,26 +491,6 @@ static inline void __acpi_ec_disable_event(struct acpi_ec *ec) 
		ec_log_drv("event blocked");

}



/*

 * Process _Q events that might have accumulated in the EC.

 * Run with locked ec mutex.

 */

static void acpi_ec_clear(struct acpi_ec *ec)

{

	int i, status;

	u8 value = 0;



	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {

		status = acpi_ec_query(ec, &value);

		if (status || !value)

			break;

	}

	if (unlikely(i == ACPI_EC_CLEAR_MAX))

		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);

	else

		pr_info("%d stale EC events cleared\n", i);

}



static void acpi_ec_enable_event(struct acpi_ec *ec)

{

	unsigned long flags;
@@ -520,10 +499,6 @@ static void acpi_ec_enable_event(struct acpi_ec *ec) 
	if (acpi_ec_started(ec))

		__acpi_ec_enable_event(ec);

	spin_unlock_irqrestore(&ec->lock, flags);



	/* Drain additional events if hardware requires that */

	if (EC_FLAGS_CLEAR_ON_RESUME)

		acpi_ec_clear(ec);

}



#ifdef CONFIG_PM_SLEEP
@@ -1740,31 +1715,6 @@ static int ec_flag_query_handshake(const struct dmi_system_id *id) 
}

#endif



/*

 * On some hardware it is necessary to clear events accumulated by the EC during

 * sleep. These ECs stop reporting GPEs until they are manually polled, if too

 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)

 *

 * https://bugzilla.kernel.org/show_bug.cgi?id=44161

 *

 * Ideally, the EC should also be instructed NOT to accumulate events during

 * sleep (which Windows seems to do somehow), but the interface to control this

 * behaviour is not known at this time.

 *

 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,

 * however it is very likely that other Samsung models are affected.

 *

 * On systems which don't accumulate _Q events during sleep, this extra check

 * should be harmless.

 */

static int ec_clear_on_resume(const struct dmi_system_id *id)

{

	pr_debug("Detected system needing EC poll on resume.\n");

	EC_FLAGS_CLEAR_ON_RESUME = 1;

	ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;

	return 0;

}



/*

 * Some ECDTs contain wrong register addresses.

 * MSI MS-171F
@@ -1782,9 +1732,6 @@ static struct dmi_system_id ec_dmi_table[] __initdata = { 
	ec_correct_ecdt, "MSI MS-171F", {

	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),

	DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},

	{

	ec_clear_on_resume, "Samsung hardware", {

	DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},

	{},

};

CRA Git | Maintained and supported by SUSTech CRA and CCSE