2020-10-29 08:53:41

by Tsuchiya Yuto

[permalink] [raw]
Subject: [PATCH 0/3] mwifiex: disable ps_mode by default for stability

Hello all,

On Microsoft Surface devices (PCIe-88W8897), we are observing stability
issues when ps_mode (IEEE power_save) is enabled, then eventually causes
firmware crash. Especially on 5GHz APs, the connection is completely
unstable and almost unusable.

I think the most desirable change is to fix the ps_mode itself. But is
seems to be hard work [1], I'm afraid we have to go this way.

Therefore, the first patch of this series disables the ps_mode by default
instead of enabling it on driver init. I'm not sure if explicitly
disabling it is really required or not. I don't have access to the details
of this chip. Let me know if it's enough to just remove the code that
enables ps_mode.

The Second patch adds a new module parameter named "allow_ps_mode". Since
other wifi drivers just disable power_save by default by module parameter
like this, I also added this.

The third patch adds a message when ps_mode will be changed. Useful when
diagnosing connection issues.

Thanks,
Tsuchiya Yuto

[1] https://bugzilla.kernel.org/show_bug.cgi?id=109681

Tsuchiya Yuto (3):
mwifiex: disable ps_mode explicitly by default instead
mwifiex: add allow_ps_mode module parameter
mwifiex: print message when changing ps_mode

.../net/wireless/marvell/mwifiex/cfg80211.c | 23 +++++++++++++++++++
.../net/wireless/marvell/mwifiex/sta_cmd.c | 11 ++++++---
2 files changed, 31 insertions(+), 3 deletions(-)

--
2.29.1


2020-10-29 19:56:34

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH 0/3] mwifiex: disable ps_mode by default for stability

On Wed, Oct 28, 2020 at 11:24:30PM +0900, Tsuchiya Yuto wrote:
> Hello all,
>
> On Microsoft Surface devices (PCIe-88W8897), we are observing stability
> issues when ps_mode (IEEE power_save) is enabled, then eventually causes
> firmware crash. Especially on 5GHz APs, the connection is completely
> unstable and almost unusable.
>
> I think the most desirable change is to fix the ps_mode itself. But is
> seems to be hard work [1], I'm afraid we have to go this way.
>
> Therefore, the first patch of this series disables the ps_mode by default
> instead of enabling it on driver init. I'm not sure if explicitly
> disabling it is really required or not. I don't have access to the details
> of this chip. Let me know if it's enough to just remove the code that
> enables ps_mode.
>
> The Second patch adds a new module parameter named "allow_ps_mode". Since
> other wifi drivers just disable power_save by default by module parameter
> like this, I also added this.
>
> The third patch adds a message when ps_mode will be changed. Useful when
> diagnosing connection issues.

> [1] https://bugzilla.kernel.org/show_bug.cgi?id=109681

Can you attach this to the actual patch as BugLink: tag?

--
With Best Regards,
Andy Shevchenko


2020-10-30 08:27:48

by Tsuchiya Yuto

[permalink] [raw]
Subject: Re: [PATCH 0/3] mwifiex: disable ps_mode by default for stability

On Wed, 2020-10-28 at 17:21 +0200, Andy Shevchenko wrote:
> On Wed, Oct 28, 2020 at 11:24:30PM +0900, Tsuchiya Yuto wrote:
> > Hello all,
> >
> > On Microsoft Surface devices (PCIe-88W8897), we are observing stability
> > issues when ps_mode (IEEE power_save) is enabled, then eventually causes
> > firmware crash. Especially on 5GHz APs, the connection is completely
> > unstable and almost unusable.
> >
> > I think the most desirable change is to fix the ps_mode itself. But is
> > seems to be hard work [1], I'm afraid we have to go this way.
> >
> > Therefore, the first patch of this series disables the ps_mode by default
> > instead of enabling it on driver init. I'm not sure if explicitly
> > disabling it is really required or not. I don't have access to the details
> > of this chip. Let me know if it's enough to just remove the code that
> > enables ps_mode.
> >
> > The Second patch adds a new module parameter named "allow_ps_mode". Since
> > other wifi drivers just disable power_save by default by module parameter
> > like this, I also added this.
> >
> > The third patch adds a message when ps_mode will be changed. Useful when
> > diagnosing connection issues.
>
> > [1] https://bugzilla.kernel.org/show_bug.cgi?id=109681
>
> Can you attach this to the actual patch as BugLink: tag?
>

Thanks! Indeed I should have added this... I wrote it in the replies.
If I send the v2 version of this series, I'll add it to them.