stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Ronald Tschalär" <ronald@innovation.ch>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	"Sasha Levin" <sashal@kernel.org>,
	linux-acpi@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 09/21] ACPI / SBS: Fix GPE storm on recent MacBookPro's
Date: Fri, 29 Mar 2019 21:31:00 -0400	[thread overview]
Message-ID: <20190330013112.784-9-sashal@kernel.org> (raw)
In-Reply-To: <20190330013112.784-1-sashal@kernel.org>

From: Ronald Tschalär <ronald@innovation.ch>

[ 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>
---
 drivers/acpi/sbs.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
index ad0b13ad4bbb..4a76000bcf7a 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;
-- 
2.19.1


  parent reply	other threads:[~2019-03-30  1:35 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-30  1:30 [PATCH AUTOSEL 4.9 01/21] gpio: pxa: handle corner case of unprobed device Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 02/21] rsi: improve kernel thread handling to fix kernel panic Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 03/21] 9p: do not trust pdu content for stat item size Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 04/21] 9p locks: add mount option for lock retry interval Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 05/21] f2fs: fix to do sanity check with current segment number Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 06/21] serial: uartps: console_setup() can't be placed to init section Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 07/21] HID: i2c-hid: override HID descriptors for certain devices Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.9 08/21] ARM: samsung: Limit SAMSUNG_PM_CHECK config option to non-Exynos platforms Sasha Levin
2019-03-30  1:31 ` Sasha Levin [this message]
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 10/21] cifs: fallback to older infolevels on findfirst queryinfo retry Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 11/21] kernel: hung_task.c: disable on suspend Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 12/21] crypto: sha256/arm - fix crash bug in Thumb2 build Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 13/21] crypto: sha512/arm " Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 14/21] iommu/dmar: Fix buffer overflow during PCI bus notification Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 15/21] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered() Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 16/21] ext4: prohibit fstrim in norecovery mode Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 17/21] lkdtm: Add tests for NULL pointer dereference Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 18/21] ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_t Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 19/21] appletalk: Fix use-after-free in atalk_proc_exit Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 20/21] lib/div64.c: off by one in shift Sasha Levin
2019-03-30  1:31 ` [PATCH AUTOSEL 4.9 21/21] include/linux/swap.h: use offsetof() instead of custom __swapoffset macro Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190330013112.784-9-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael.j.wysocki@intel.com \
    --cc=ronald@innovation.ch \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).