From: Stanislaw Gruszka <sgruszka@redhat.com>
To: Felix Fietkau <nbd@nbd.name>
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>,
Kalle Valo <kvalo@codeaurora.org>,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH v2 0/7] mt76x02: Beacon support for USB
Date: Wed, 30 Jan 2019 11:07:49 +0100 [thread overview]
Message-ID: <20190130100748.GA5655@redhat.com> (raw)
In-Reply-To: <ae2324b4-e79c-6984-b29e-5fef77ede672@nbd.name>
On Wed, Jan 30, 2019 at 10:16:34AM +0100, Felix Fietkau wrote:
> On 2019-01-30 09:37, Stanislaw Gruszka wrote:
> > On Tue, Jan 29, 2019 at 01:40:57PM +0100, Lorenzo Bianconi wrote:
> >> > Felix Fietkau <nbd@nbd.name> writes:
> >> >
> >> > > On 2019-01-29 13:07, Kalle Valo wrote:
> >> > >> Felix Fietkau <nbd@nbd.name> writes:
> >> > >>
> >> > >>> On 2019-01-29 12:47, Kalle Valo wrote:
> >> > >>>> Stanislaw Gruszka <sgruszka@redhat.com> writes:
> >> > >>>>
> >> > >>>>> We can configure beaconing, but without TBTT interrupt we
> >> > >>>>> can not support PS buffering. This can be added later using
> >> > >>>>> kernel hrtimer, if we can keep it in sycn with device timer.
> >> > >>>>>
> >> > >>>>> I tested AP and IBSS modes.
> >> > >>>>
> >> > >>>> So how does this work reliably so that there's no packet loss with
> >> > >>>> clients using power save?
> >> > >>>
> >> > >>> There will be multicast packet loss for clients using power save.
> >> > >>
> >> > >> Isn't that a problem? At least as a normal user I would very frustrated
> >> > >> if sometimes my connection work and sometimes not, for example if I'm
> >> > >> trying discover devices from my network. Hopefully nobody won't use USB
> >> > >> devices for any real AP stuff, but still enabling something which we
> >> > >> know doesn't work realiably is concerning.
> >> > >
> >> > > I agree. Maybe we should leave out the flag for AP mode in this patch
> >> > > until we have PS buffering and leave the rest of the code intact.
> >> >
> >> > At least for me that sounds good.
> >>
> >> We can support ps buffering in AP as well using a hrtimer. In this way we
> >> can reuse most of the existing code
> >
> > Yes, but there is issue to address, since kernel timer and device TBT
> > timer are independed, they possibly can get out of sync after some time,
> > for example few hours or days. So there is need to prevent/fix this
> > somehow.
> We could read the TSF timer value from the hardware and sync the hrtimer
> against that.
Ok then. I'll implement hrtimer solution and repost this set. Patch
6 will no longer be necessery.
Regards
Stanislaw
next prev parent reply other threads:[~2019-01-30 10:12 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-28 12:21 [PATCH v2 0/7] mt76x02: Beacon support for USB Stanislaw Gruszka
2019-01-28 12:21 ` [PATCH v2 1/7] mt76x02: use mask for vifs Stanislaw Gruszka
2019-01-28 13:35 ` Lorenzo Bianconi
2019-01-28 14:23 ` Stanislaw Gruszka
2019-01-28 14:31 ` Lorenzo Bianconi
2019-01-28 12:21 ` [PATCH v2 2/7] mt76x02: use commmon add interface for mt76x2u Stanislaw Gruszka
2019-01-28 12:21 ` [PATCH v2 3/7] mt76x02: initialize mutli bss mode when set up address Stanislaw Gruszka
2019-01-28 12:21 ` [PATCH v2 4/7] mt76x02: minor beaconing init changes Stanislaw Gruszka
2019-01-28 12:21 ` [PATCH v2 5/7] mt76x02: init beacon config for mt76x2u Stanislaw Gruszka
2019-01-28 12:21 ` [PATCH v2 6/7] mt76: beaconing fixes for USB Stanislaw Gruszka
2019-01-28 13:44 ` Lorenzo Bianconi
2019-01-28 12:21 ` [PATCH v2 7/7] mt76x02: enable support for IBSS, AP and MESH Stanislaw Gruszka
2019-01-29 11:47 ` [PATCH v2 0/7] mt76x02: Beacon support for USB Kalle Valo
2019-01-29 11:49 ` Felix Fietkau
2019-01-29 12:07 ` Kalle Valo
2019-01-29 12:10 ` Felix Fietkau
2019-01-29 12:18 ` Kalle Valo
2019-01-29 12:40 ` Lorenzo Bianconi
2019-01-30 8:37 ` Stanislaw Gruszka
2019-01-30 9:16 ` Felix Fietkau
2019-01-30 10:07 ` Stanislaw Gruszka [this message]
2019-01-30 15:22 ` Stanislaw Gruszka
2019-02-05 14:58 ` Stanislaw Gruszka
2019-01-30 8:29 ` Stanislaw Gruszka
2019-01-30 9:25 ` Felix Fietkau
2019-01-30 10:27 ` Kalle Valo
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