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authorRonald Tschalär <ronald@innovation.ch>2018-09-30 19:52:51 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-27 09:33:58 +0200
commitc49c3925a8462a9804bf6e498af39378b619b095 (patch)
treebe36efa19725fb759b6c15c62eecbde52a2eb506 /drivers/acpi
parent1e3975db46daaf51e1fd35ae8b69b304895eeddd (diff)
ACPI / SBS: Fix GPE storm on recent MacBookPro's
[ Upstream commit ca1721c5bee77105829cbd7baab8ee0eab85b06d ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/sbs.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
index cb3dedb1beae..b133dac8a7f2 100644
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -443,9 +443,13 @@ 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;