linux-kernel - RE: [PATCH RFC v1 2/7] rtw88: Use rtw_iterate_vifs where the iterator reads or writes registers

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Date:   Mon, 26 Jul 2021 07:22:45 +0000
From:   Pkshih <pkshih@...ltek.com>
To:     Martin Blumenstingl <martin.blumenstingl@...glemail.com>
CC:     "linux-wireless@...r.kernel.org" <linux-wireless@...r.kernel.org>,
        "tony0620emma@...il.com" <tony0620emma@...il.com>,
        "kvalo@...eaurora.org" <kvalo@...eaurora.org>,
        "johannes@...solutions.net" <johannes@...solutions.net>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Neo Jou <neojou@...il.com>,
        Jernej Skrabec <jernej.skrabec@...il.com>
Subject: RE: [PATCH RFC v1 2/7] rtw88: Use rtw_iterate_vifs where the iterator reads or writes registers


> -----Original Message-----
> From: Martin Blumenstingl [mailto:martin.blumenstingl@...glemail.com]
> Sent: Monday, July 26, 2021 5:31 AM
> To: Pkshih
> Cc: linux-wireless@...r.kernel.org; tony0620emma@...il.com; kvalo@...eaurora.org;
> johannes@...solutions.net; netdev@...r.kernel.org; linux-kernel@...r.kernel.org; Neo Jou; Jernej
> Skrabec
> Subject: Re: [PATCH RFC v1 2/7] rtw88: Use rtw_iterate_vifs where the iterator reads or writes registers
> 
> Hello Ping-Ke,
> 
> On Mon, Jul 19, 2021 at 7:47 AM Pkshih <pkshih@...ltek.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Martin Blumenstingl [mailto:martin.blumenstingl@...glemail.com]
> > > Sent: Sunday, July 18, 2021 4:41 AM
> > > To: linux-wireless@...r.kernel.org
> > > Cc: tony0620emma@...il.com; kvalo@...eaurora.org; johannes@...solutions.net;
> netdev@...r.kernel.org;
> > > linux-kernel@...r.kernel.org; Neo Jou; Jernej Skrabec; Martin Blumenstingl
> > > Subject: [PATCH RFC v1 2/7] rtw88: Use rtw_iterate_vifs where the iterator reads or writes registers
> > >
> > > Upcoming SDIO support may sleep in the read/write handlers. Switch
> > > all users of rtw_iterate_vifs_atomic() which are either reading or
> > > writing a register to rtw_iterate_vifs().
> > >
> > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
> > > ---
> > >  drivers/net/wireless/realtek/rtw88/main.c | 6 +++---
> > >  drivers/net/wireless/realtek/rtw88/ps.c   | 2 +-
> > >  2 files changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/net/wireless/realtek/rtw88/main.c
> b/drivers/net/wireless/realtek/rtw88/main.c
> > > index c6364837e83b..207161a8f5bd 100644
> > > --- a/drivers/net/wireless/realtek/rtw88/main.c
> > > +++ b/drivers/net/wireless/realtek/rtw88/main.c
> > > @@ -229,8 +229,8 @@ static void rtw_watch_dog_work(struct work_struct *work)
> > >       rtw_phy_dynamic_mechanism(rtwdev);
> > >
> > >       data.rtwdev = rtwdev;
> > > -     /* use atomic version to avoid taking local->iflist_mtx mutex */
> > > -     rtw_iterate_vifs_atomic(rtwdev, rtw_vif_watch_dog_iter, &data);
> > > +
> > > +     rtw_iterate_vifs(rtwdev, rtw_vif_watch_dog_iter, &data);
> >
> > You revert the fix of [1].
> Thanks for bringing this to my attention!
> 
> > I think we can move out rtw_chip_cfg_csi_rate() from rtw_dynamic_csi_rate(), and
> > add/set a field cfg_csi_rate to itera data. Then, we do rtw_chip_cfg_csi_rate()
> > outside iterate function. Therefore, we can keep the atomic version of iterate_vifs.
> just to make sure that I understand this correctly:
> rtw_iterate_vifs_atomic can be the iterator as it was before
> inside the iterator func I use something like:
>     iter_data->cfg_csi_rate = rtwvif->bfee.role == RTW_BFEE_SU ||
> rtwvif->bfee.role == RTW_BFEE_MU || iter_data->cfg_csi_rate;
> (the last iter_data->cfg_csi_rate may read a bit strange, but I think
> it's needed because there can be multiple interfaces and if any of
> them has cfg_csi_rate true then we need to remember that)
> then move the rtw_chip_cfg_csi_rate outside the iterator function,
> taking iter_data->cfg_csi_rate to decide whether it needs to be called
> 

Yes, you understand correctly.

For the strange part that you mentioned, how about this?
iter_data->cfg_csi_rate |= rtwvif->bfee.role == RTW_BFEE_SU ||
                           rtwvif->bfee.role == RTW_BFEE_MU;

--
Ping-Ke