ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook
Commit7bc5a2bad0
'ACPI: Support _OSI("Darwin") correctly' caused the MacBook firmware to expose the SBS, resulting in intermittent hangs of several minutes on boot, and failure to detect or report the battery. Fix this by adding a 5 us delay to the start of each SMBUS transaction. This timing is the result of experimentation - hangs were observed with 3 us but never with 5 us. Fixes:7bc5a2bad0
'ACPI: Support _OSI("Darwin") correctly' Link: https://bugzilla.kernel.org/show_bug.cgi?id=94651 Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com> Cc: 3.18+ <stable@vger.kernel.org> # 3.18+ [ rjw: Subject and changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
parent
61f8ff6939
commit
3349fb64b2
|
@ -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;
|
||||
|
||||
|
|
Loading…
Reference in a new issue