diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index e629e891d1bb..a6366d3f0c78 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -133,7 +133,7 @@ static unsigned int ec_storm_threshold  __read_mostly = 8;
 module_param(ec_storm_threshold, uint, 0644);
 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 
-static bool ec_freeze_events __read_mostly = false;
+static bool ec_freeze_events __read_mostly;
 module_param(ec_freeze_events, bool, 0644);
 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 
@@ -177,7 +177,7 @@ struct acpi_ec *first_ec;
 EXPORT_SYMBOL(first_ec);
 
 static struct acpi_ec *boot_ec;
-static bool boot_ec_is_ecdt = false;
+static bool boot_ec_is_ecdt;
 static struct workqueue_struct *ec_wq;
 static struct workqueue_struct *ec_query_wq;
 
@@ -2152,6 +2152,13 @@ static const struct dmi_system_id acpi_ec_no_wakeup[] = {
 			DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
 		},
 	},
+	{
+		.ident = "HP ZHAN 66 Pro",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+			DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
+		},
+	},
 	{ },
 };
 
diff --git a/drivers/acpi/pmic/intel_pmic.c b/drivers/acpi/pmic/intel_pmic.c
index a371f273f99d..9cde299eba88 100644
--- a/drivers/acpi/pmic/intel_pmic.c
+++ b/drivers/acpi/pmic/intel_pmic.c
@@ -211,31 +211,36 @@ static acpi_status intel_pmic_regs_handler(u32 function,
 		void *handler_context, void *region_context)
 {
 	struct intel_pmic_opregion *opregion = region_context;
-	int result = 0;
+	int result = -EINVAL;
 
-	switch (address) {
-	case 0:
-		return AE_OK;
-	case 1:
-		opregion->ctx.addr |= (*value64 & 0xff) << 8;
-		return AE_OK;
-	case 2:
-		opregion->ctx.addr |= *value64 & 0xff;
-		return AE_OK;
-	case 3:
-		opregion->ctx.val = *value64 & 0xff;
-		return AE_OK;
-	case 4:
-		if (*value64) {
-			result = regmap_write(opregion->regmap, opregion->ctx.addr,
-					      opregion->ctx.val);
-		} else {
-			result = regmap_read(opregion->regmap, opregion->ctx.addr,
-					     &opregion->ctx.val);
-			if (result == 0)
-				*value64 = opregion->ctx.val;
+	if (function == ACPI_WRITE) {
+		switch (address) {
+		case 0:
+			return AE_OK;
+		case 1:
+			opregion->ctx.addr |= (*value64 & 0xff) << 8;
+			return AE_OK;
+		case 2:
+			opregion->ctx.addr |= *value64 & 0xff;
+			return AE_OK;
+		case 3:
+			opregion->ctx.val = *value64 & 0xff;
+			return AE_OK;
+		case 4:
+			if (*value64) {
+				result = regmap_write(opregion->regmap, opregion->ctx.addr,
+						      opregion->ctx.val);
+			} else {
+				result = regmap_read(opregion->regmap, opregion->ctx.addr,
+						     &opregion->ctx.val);
+			}
+			opregion->ctx.addr = 0;
 		}
-		memset(&opregion->ctx, 0x00, sizeof(opregion->ctx));
+	}
+
+	if (function == ACPI_READ && address == 3) {
+		*value64 = opregion->ctx.val;
+		return AE_OK;
 	}
 
 	if (result < 0) {
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 33474fd96991..068e393ea0c6 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -115,7 +115,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	 */
 	{
 	 .callback = video_detect_force_vendor,
-	 .ident = "X360",
+	 /* X360 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
@@ -124,7 +124,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_vendor,
-	.ident = "Asus UL30VT",
+	/* Asus UL30VT */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
@@ -132,7 +132,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_vendor,
-	.ident = "Asus UL30A",
+	/* Asus UL30A */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
@@ -140,7 +140,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_vendor,
-	.ident = "GIGABYTE GB-BXBT-2807",
+	/* GIGABYTE GB-BXBT-2807 */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
@@ -148,12 +148,20 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_vendor,
-	.ident = "Sony VPCEH3U1E",
+	/* Sony VPCEH3U1E */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
 		},
 	},
+	{
+	.callback = video_detect_force_vendor,
+	/* Xiaomi Mi Pad 2 */
+	.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
+		},
+	},
 
 	/*
 	 * These models have a working acpi_video backlight control, and using
@@ -164,7 +172,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	 */
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "ThinkPad T420",
+	 /* ThinkPad T420 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
@@ -172,7 +180,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "ThinkPad T520",
+	 /* ThinkPad T520 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
@@ -180,7 +188,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "ThinkPad X201s",
+	 /* ThinkPad X201s */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
@@ -188,7 +196,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "ThinkPad X201T",
+	 /* ThinkPad X201T */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
@@ -199,7 +207,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
 	 .callback = video_detect_force_video,
-	 .ident = "HP ENVY 15 Notebook",
+	 /* HP ENVY 15 Notebook */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
@@ -207,7 +215,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
+	 /* SAMSUNG 870Z5E/880Z5E/680Z5E */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
@@ -215,7 +223,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
+	 /* SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME,
@@ -225,7 +233,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
+	 /* SAMSUNG 3570R/370R/470R/450R/510R/4450RV */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME,
@@ -235,7 +243,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 670Z5E",
+	 /* SAMSUNG 670Z5E */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
@@ -244,7 +252,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 730U3E/740U3E",
+	 /* SAMSUNG 730U3E/740U3E */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
@@ -253,7 +261,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
+	 /* SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME,
@@ -263,7 +271,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
 	 .callback = video_detect_force_video,
-	 .ident = "Dell XPS14 L421X",
+	 /* Dell XPS14 L421X */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
@@ -272,7 +280,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
 	 .callback = video_detect_force_video,
-	 .ident = "Dell XPS15 L521X",
+	 /* Dell XPS15 L521X */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
@@ -281,7 +289,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
 	 .callback = video_detect_force_video,
-	 .ident = "SAMSUNG 530U4E/540U4E",
+	 /* SAMSUNG 530U4E/540U4E */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
@@ -290,7 +298,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	/* https://bugs.launchpad.net/bugs/1894667 */
 	{
 	 .callback = video_detect_force_video,
-	 .ident = "HP 635 Notebook",
+	 /* HP 635 Notebook */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
@@ -301,7 +309,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
 	 .callback = video_detect_force_native,
-	 .ident = "Lenovo Ideapad S405",
+	 /* Lenovo Ideapad S405 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
@@ -310,7 +318,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
 	 .callback = video_detect_force_native,
-	 .ident = "Lenovo Ideapad Z570",
+	 /* Lenovo Ideapad Z570 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
@@ -318,7 +326,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
-	 .ident = "Lenovo E41-25",
+	 /* Lenovo E41-25 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
@@ -326,7 +334,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
-	 .ident = "Lenovo E41-45",
+	 /* Lenovo E41-45 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
@@ -335,7 +343,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
 	 .callback = video_detect_force_native,
-	 .ident = "Apple MacBook Pro 12,1",
+	 /* Apple MacBook Pro 12,1 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
@@ -343,7 +351,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
-	 .ident = "Dell Vostro V131",
+	 /* Dell Vostro V131 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
@@ -352,7 +360,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
 	 .callback = video_detect_force_native,
-	 .ident = "Dell XPS 17 L702X",
+	 /* Dell XPS 17 L702X */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
@@ -360,7 +368,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
-	 .ident = "Dell Precision 7510",
+	 /* Dell Precision 7510 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
@@ -368,7 +376,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
-	 .ident = "Acer Aspire 5738z",
+	 /* Acer Aspire 5738z */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
@@ -378,7 +386,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	{
 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
 	 .callback = video_detect_force_native,
-	 .ident = "Acer TravelMate 5735Z",
+	 /* Acer TravelMate 5735Z */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
@@ -387,7 +395,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_native,
-	.ident = "ASUSTeK COMPUTER INC. GA401",
+	/* ASUSTeK COMPUTER INC. GA401 */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
@@ -395,7 +403,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_native,
-	.ident = "ASUSTeK COMPUTER INC. GA502",
+	/* ASUSTeK COMPUTER INC. GA502 */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
@@ -403,7 +411,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	.callback = video_detect_force_native,
-	.ident = "ASUSTeK COMPUTER INC. GA503",
+	/* ASUSTeK COMPUTER INC. GA503 */
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
@@ -416,7 +424,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	 */
 	{
 	 .callback = video_detect_force_none,
-	 .ident = "Dell OptiPlex 9020M",
+	 /* Dell OptiPlex 9020M */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
@@ -424,7 +432,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_none,
-	 .ident = "MSI MS-7721",
+	 /* MSI MS-7721 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
 		DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
diff --git a/include/acpi/platform/acgcc.h b/include/acpi/platform/acgcc.h
index 20ecb004f5a4..33ad282bd338 100644
--- a/include/acpi/platform/acgcc.h
+++ b/include/acpi/platform/acgcc.h
@@ -10,25 +10,12 @@
 #ifndef __ACGCC_H__
 #define __ACGCC_H__
 
-/*
- * Use compiler specific <stdarg.h> is a good practice for even when
- * -nostdinc is specified (i.e., ACPI_USE_STANDARD_HEADERS undefined.
- */
 #ifndef va_arg
-#ifdef ACPI_USE_BUILTIN_STDARG
-typedef __builtin_va_list va_list;
-#define va_start(v, l)          __builtin_va_start(v, l)
-#define va_end(v)               __builtin_va_end(v)
-#define va_arg(v, l)            __builtin_va_arg(v, l)
-#define va_copy(d, s)           __builtin_va_copy(d, s)
-#else
 #ifdef __KERNEL__
 #include <linux/stdarg.h>
 #else
-/* Used to build acpi tools */
 #include <stdarg.h>
 #endif /* __KERNEL__ */
-#endif /* ACPI_USE_BUILTIN_STDARG */
 #endif /* ! va_arg */
 
 #define ACPI_INLINE             __inline__