diff options
| author | Ronald Tschalär | 2018-09-30 19:52:51 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki | 2018-10-08 08:41:35 +0200 |
| commit | ca1721c5bee77105829cbd7baab8ee0eab85b06d (patch) | |
| tree | 7822b0e00f9013f90442bbec0a7b16949fe059ab /drivers/acpi | |
| parent | 0238df646e6224016a45505d2c111a24669ebe21 (diff) | |
ACPI / SBS: Fix GPE storm on recent MacBookPro's
On Apple machines, plugging-in or unplugging the power triggers a GPE
for the EC. Since these machines expose an SBS device, this GPE ends
up triggering the acpi_sbs_callback(). This in turn tries to get the
status of the SBS charger. However, on MBP13,* and MBP14,* machines,
performing the smbus-read operation to get the charger's status triggers
the EC's GPE again. The result is an endless re-triggering and handling
of that GPE, consuming significant CPU resources (> 50% in irq).
In the end this is quite similar to commit 3031cddea633 (ACPI / SBS:
Don't assume the existence of an SBS charger), except that on the above
machines a status of all 1's is returned. And like there, we just want
ignore the charger here.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=198169
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/sbs.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c index 295b59271189..96c5e27967f4 100644 --- a/drivers/acpi/sbs.c +++ b/drivers/acpi/sbs.c @@ -441,9 +441,13 @@ static int acpi_ac_get_present(struct acpi_sbs *sbs) /* * The spec requires that bit 4 always be 1. If it's not set, assume - * that the implementation doesn't support an SBS charger + * that the implementation doesn't support an SBS charger. + * + * And on some MacBooks a status of 0xffff is always returned, no + * matter whether the charger is plugged in or not, which is also + * wrong, so ignore the SBS charger for those too. */ - if (!((status >> 4) & 0x1)) + if (!((status >> 4) & 0x1) || status == 0xffff) return -ENODEV; sbs->charger_present = (status >> 15) & 0x1; |