Commit 79149001 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI / EC: Fix regression due to conflicting firmware behavior between Samsung and Acer. 

It is reported that Samsung laptops that need to poll events are broken by
the following commit:
 Commit 3afcf2ec
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued when SCI_EVT isn't set

The behaviors of the 2 vendor firmwares are conflict:
 1. Acer: OSPM shouldn't issue QR_EC unless SCI_EVT is set, firmware
         automatically sets SCI_EVT as long as there is event queued up.
 2. Samsung: OSPM should issue QR_EC whatever SCI_EVT is set, firmware
            returns 0 when there is no event queued up.

This patch is a quick fix to distinguish the behaviors to make Acer
behavior only effective for Acer EC firmware so that the breakages on
Samsung EC firmware can be avoided.

Fixes: 3afcf2ec (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161


Reported-and-tested-by: default avatarOrtwin Glück <odi@odi.ch>
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
[ rjw : Subject ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent df9ff918

drivers/acpi/ec.c

+18 −7
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */ 
static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */

static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */

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 */



/* --------------------------------------------------------------------------

 *                           Transaction Management
@@ -236,13 +237,8 @@ static bool advance_transaction(struct acpi_ec *ec) 
		}

		return wakeup;

	} else {

		/*

		 * There is firmware refusing to respond QR_EC when SCI_EVT

		 * is not set, for which case, we complete the QR_EC

		 * without issuing it to the firmware.

		 * https://bugzilla.kernel.org/show_bug.cgi?id=86211

		 */

		if (!(status & ACPI_EC_FLAG_SCI) &&

		if (EC_FLAGS_QUERY_HANDSHAKE &&

		    !(status & ACPI_EC_FLAG_SCI) &&

		    (t->command == ACPI_EC_COMMAND_QUERY)) {

			t->flags |= ACPI_EC_COMMAND_POLL;

			t->rdata[t->ri++] = 0x00;
@@ -1011,6 +1007,18 @@ static int ec_enlarge_storm_threshold(const struct dmi_system_id *id) 
	return 0;

}



/*

 * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for

 * which case, we complete the QR_EC without issuing it to the firmware.

 * https://bugzilla.kernel.org/show_bug.cgi?id=86211

 */

static int ec_flag_query_handshake(const struct dmi_system_id *id)

{

	pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");

	EC_FLAGS_QUERY_HANDSHAKE = 1;

	return 0;

}



/*

 * 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
@@ -1085,6 +1093,9 @@ static struct dmi_system_id ec_dmi_table[] __initdata = { 
	{

	ec_clear_on_resume, "Samsung hardware", {

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

	{

	ec_flag_query_handshake, "Acer hardware", {

	DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},

	{},

};

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