Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 5 May 2023 13:27:39 +0800
From:   Kevin Lo <kevlo@kevlo.org>
To:     Ping-Ke Shih <pkshih@realtek.com>
Cc:     Kalle Valo <kvalo@kernel.org>,
        "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        Bitterblue Smith <rtl8821cerfe2@gmail.com>,
        Jes Sorensen <Jes.Sorensen@gmail.com>
Subject: Re: [PATCH v2] wifi: rtl8xxxu: 8188f: no need to initialize
 interrupts
Message-ID: <ZFSTy4hi/RZ4tIel@ns.kevlo.org>
References: <ZEswqUHBXPHC/znL@ns.kevlo.org>
 <87ildgpnsd.fsf@kernel.org>
 <ZEtpDi8oCr0E9scd@ns.kevlo.org>
 <02a6f536d1a144749d97db5c301ee76c@realtek.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <02a6f536d1a144749d97db5c301ee76c@realtek.com>
Precedence: bulk

On Tue, May 02, 2023 at 09:10:04AM +0000, Ping-Ke Shih wrote:
> 
> 
> 
> > -----Original Message-----
> > From: Kevin Lo <kevlo@kevlo.org>
> > Sent: Friday, April 28, 2023 2:35 PM
> > To: Kalle Valo <kvalo@kernel.org>
> > Cc: linux-wireless@vger.kernel.org; Bitterblue Smith <rtl8821cerfe2@gmail.com>; Jes Sorensen
> > <Jes.Sorensen@gmail.com>; Ping-Ke Shih <pkshih@realtek.com>
> > Subject: Re: [PATCH v2] wifi: rtl8xxxu: 8188f: no need to initialize interrupts
> > 
> > On Fri, Apr 28, 2023 at 08:40:34AM +0300, Kalle Valo wrote:
> > >
> > > Kevin Lo <kevlo@kevlo.org> writes:
> > >
> > > > There's no need to initialize interrupts for RTL8188FTV like the vendor driver.
> > > >
> > > > Signed-off-by: Kevin Lo <kevlo@kevlo.org>
> > >
> > > Why do this, what's the benefit? Or is this just a theoretical fix. The
> > > commit log should explain this.
> > 
> > If I understand correctly, just like rtw88 usb devices, rtl8xxxu has no
> > hardware interrupt.
> > 
> 
> With/without hardware interrupt, it depends on IMR (interrupt mask register)
> setting. If it is enabled, driver can receive C2H, PS indicators, and beacon
> TBTT events via certain USB endpoint. But, normally vendor driver doesn't
> use them neither.
> 
> Why it initializes interrupt in this patch is to reset ISR (interrupt status
> register) to avoid unexpected interrupts are received. So, if it doesn't
> really enable interrupt by IMR, I suppose it should work well even without
> this patch.
> 
> Kevin, could I know the real problem you met?

Ping-Ke, many thanks for the clear explanation.

I didn't encounter any problems.  As you mentioned, while the vendor driver
doesn't have IMR settings, there is no harm in initializing interrupts.
Please drop this patch, thanks.

> Ping-Ke

Regards,
Kevin