Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> writes:
> On Sat, Feb 03, 2018 at 07:25:54PM +0100, Markus Demleitner wrote:
>
>> It's 662591461c4b9a1e3b9b159dbf37648a585ebaae. To my eyes, it even
>> looks plausible that it's causing the problematic behaviour, but
>> since I can't say I understand what I'd be doing if I dabbled with
>> the change, I've refrained from guessing how to fix it.
>>
>> I'm happy to try patches, though.
>
> Ok, thanks. I've added the authors of this patch to the email here,
> perhaps they have an idea of what is going on?
This thing made me curious enough to dive into code I don't understand,
as I have experienced the annoying crazy fan behaviour in resume a few
times on my X1 Carbon 4th gen.
Maybe I missed something, but it looks like commit
c3a696b6e8f8 ("ACPI / EC: Use busy polling mode when GPE is not enabled")
introduced suspend/resume busy polling for the "boot EC" unintentionally?
The patch moved acpi_ec_leave_noirq() and acpi_ec_leave_noirq()
functions outside the #ifdef CONFIG_PM_SLEEP, so they could be reused
while installing handlers. But when doing that the
if (ec == first_ec)
conditions on suspend/resume were silently dropped. I assume the
intention might have been to move those intto acpi_ec_suspend_noirq()
and acpi_ec_resume_noirq() instead? But that didn't happen AFAICS.
Or did I misunderstand this completely? Not unlikely given that I have
zero clue about what this code is doing...
But I do wonder if the attached (completely untested!!) patch makes
things any better?
Bjørn
>From 82b8f437a243854a3f1d3c82f85520fd2b788881 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@xxxxxxx>
Date: Sun, 4 Feb 2018 21:15:36 +0100
Subject: [PATCH] Revert "ACPI / EC: Drop EC noirq hooks to fix a regression"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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This reverts commit 662591461c4b9a1e3b9b159dbf37648a585ebaae
and re-introduce the conditions dropped by commit c3a696b6e8f8
("ACPI / EC: Use busy polling mode when GPE is not enabled")
Fixes: c3a696b6e8f8 ("ACPI / EC: Use busy polling mode when GPE is not enabled")
Signed-off-by: Bjørn Mork <bjorn@xxxxxxx>
---
drivers/acpi/ec.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d9f38c645e4a..24a772f66847 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1905,6 +1905,26 @@ int __init acpi_ec_ecdt_probe(void)
}
#ifdef CONFIG_PM_SLEEP
+static int acpi_ec_suspend_noirq(struct device *dev)
+{
+ struct acpi_ec *ec =
+ acpi_driver_data(to_acpi_device(dev));
+
+ if (ec == first_ec)
+ acpi_ec_enter_noirq(ec);
+ return 0;
+}
+
+static int acpi_ec_resume_noirq(struct device *dev)
+{
+ struct acpi_ec *ec =
+ acpi_driver_data(to_acpi_device(dev));
+
+ if (ec == first_ec)
+ acpi_ec_leave_noirq(ec);
+ return 0;
+}
+
static int acpi_ec_suspend(struct device *dev)
{
struct acpi_ec *ec =
--
2.11.0
