ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook (3349fb64) · Commits · 戴 / test

drivers/acpi/sbshc.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		#include <linux/delay.h>
		#include <linux/module.h>
		#include <linux/interrupt.h>
		#include <linux/dmi.h>
		#include "sbshc.h"

		#define PREFIX "ACPI: "
		@@ -87,6 +88,8 @@ enum acpi_smb_offset {
		ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
		};

		static bool macbook;

		static inline int smb_hc_read(struct acpi_smb_hc hc, u8 address, u8 data)
		{
		return ec_read(hc->offset + address, data);
		@@ -132,6 +135,8 @@ static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
		}

		mutex_lock(&hc->lock);
		if (macbook)
		udelay(5);
		if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
		goto end;
		if (temp) {
		@@ -257,12 +262,29 @@ extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
		acpi_handle handle, acpi_ec_query_func func,
		void *data);

		static int macbook_dmi_match(const struct dmi_system_id *d)
		{
		pr_debug("Detected MacBook, enabling workaround\n");
		macbook = true;
		return 0;
		}

		static struct dmi_system_id acpi_smbus_dmi_table[] = {
		{ macbook_dmi_match, "Apple MacBook", {
		DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
		DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
		},
		{ },
		};

		static int acpi_smbus_hc_add(struct acpi_device *device)
		{
		int status;
		unsigned long long val;
		struct acpi_smb_hc *hc;

		dmi_check_system(acpi_smbus_dmi_table);

		if (!device)
		return -EINVAL;