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From:   Tony Chuang <yhchuang@realtek.com>
To:     Kalle Valo <kvalo@codeaurora.org>
CC:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        "briannorris@chromium.org" <briannorris@chromium.org>,
        Arend Van Spriel <arend.vanspriel@broadcom.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        "tamizhr@codeaurora.org" <tamizhr@codeaurora.org>
Subject: RE: [PATCH v2 2/2] rtw88: add a debugfs entry to enable/disable coex mechanism
Thread-Topic: [PATCH v2 2/2] rtw88: add a debugfs entry to enable/disable coex
 mechanism
Thread-Index: AQHV9eid5DTKsHzIFkaU/75iZgvikahFRc8AgAEbR4CAEQe7sA==
Date:   Tue, 24 Mar 2020 07:05:04 +0000
Message-ID: <79e3276a8bfe4cc1bb2788668cfd16d2@realtek.com>
References: <20200309075852.11454-1-yhchuang@realtek.com>
        <20200309075852.11454-3-yhchuang@realtek.com>
        <877dzpu2lt.fsf@tynnyri.adurom.net>
        <33d4904b71a04ed8b0226ce07b037e05@realtek.com>
 <87a74ko66i.fsf@kamboji.qca.qualcomm.com>
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> Tony Chuang <yhchuang@realtek.com> writes:
> 
> > Kalle Valo <kvalo@codeaurora.org> :
> >
> >> <yhchuang@realtek.com> writes:
> >>
> >> > From: Yan-Hsuan Chuang <yhchuang@realtek.com>
> >> >
> >> > Sometimes we need to stop the coex mechanism to debug, so that we
> >> > can manually control the device through various outer commands.
> >> > Hence, add a new debugfs coex_enable to allow us to enable/disable
> >> > the coex mechanism when driver is running.
> >> >
> >> > To disable coex
> >> > echo 0 > /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable
> >> >
> >> > To enable coex
> >> > echo 1 > /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable
> >> >
> >> > To check coex dm is enabled or not
> >> > cat /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable
> >>
> >> I forgot, did we add a command to nl80211 for managing btcoex? At least
> >> we have talking about that for years. Please check that first before
> >> adding a debugfs interface for this.
> >>
> >
> > Yes, I found there was a thread [1] talking about adding a callback to
> > enable/disable btcoex, but it seems not get applied eventually.
> 
> Too bad, I really think we should have at least enable/disable
> functionality in nl80211. But if it's not there, I guess it's ok to have
> yet another driver custom debugfs file :/
> 
> > And there's another thread [2] talking about add a btcoex subsystem.
> > But seems like nobody can implement it cleanly in the host.
> >
> > I think adding btcoex subsystem could have a lot of pain since each
> > vendor is using different mechanism controlling the btcoex, and it
> > usually comes with RF related design which is difficult to write a common
> > function to deal with all kinds of them.
> 
> Yeah, btcoex subsystem is a big challenge.
> 

So I think we can take this patch set.
It is really useful to debug on coex's issues.

Yen-Hsuan