[Unstable] [PATCH] UBUNTU: [Config] CONFIG_SATA_MOBILE_LPM_POLICY=3
Kai Heng Feng
kai.heng.feng at canonical.com
Thu Mar 29 04:00:44 UTC 2018
> On Mar 29, 2018, at 1:32 AM, Seth Forshee <seth.forshee at canonical.com>
> On Wed, Mar 28, 2018 at 07:21:04PM +0800, Kai-Heng Feng wrote:
>> BugLink: https://bugs.launchpad.net/bugs/1759547
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
>> debian.master/config/config.common.ubuntu | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> diff --git a/debian.master/config/config.common.ubuntu
>> index e09a65ef0a1f..98a828b82f30 100644
>> --- a/debian.master/config/config.common.ubuntu
>> +++ b/debian.master/config/config.common.ubuntu
>> @@ -7691,7 +7691,7 @@ CONFIG_SATA_DWC=m
> From the commit message of the patch adding this:
> Also enabling LPM by default is not entirely without risk of
> regressions. At least min_power is known to cause issues with some
> disks, including some reports of data corruption.
> Is there any risk of these issues with the value you've chosen here?
Yes, users in  can't mount rootfs with min_power.
I wrote a patch to quirk their devices to use med_power_with_dipm (i.e.
unfortunately their disk still have issues with this setting.
So yes, some disks are buggy under both min_power and med_power_with_dipm.
Since LPM can be set from userspace (e.g. laptop-mode-tools, TLP, powertop),
user will likely to get hit by this bug, one way or another.
In a discussion with Hans , he mentioned that Fedora will use
CONFIG_SATA_MOBILE_LPM_POLICY=3 from v4.15+,
I think we should do the same.
Also, one of our customer does want us to use a saner default for laptops.
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