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Date:   Sat, 16 Jul 2022 14:13:34 +0200
From:   Reinhard Speyerer <rspmn@arcor.de>
To:     sdlyyxy <sdlyyxy@bupt.edu.cn>
Cc:     johan@kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: usb-serial-simple: add new device id for OPPO R11
Message-ID: <YtKrbucYNulPEKUp@arcor.de>
References: <20220715142444.4173681-1-gregkh@linuxfoundation.org>
 <119D7B0F-7809-464A-AFF1-DF72FFF9E63F@bupt.edu.cn>
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On Fri, Jul 15, 2022 at 10:59:13PM +0800, sdlyyxy wrote:
> 
> > On Jul 15, 2022, at 22:24, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> > 
> > The Oppo R11 diagnostic USB connection needs to be bound to the
> > usb-serial-simple driver as it just wants to use a dumb pipe to
> > communicate to the host.
> > 
> > usb-devices output:
> > T: Bus=03 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 10 Spd=480 MxCh= 0
> > D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
> > P: Vendor=22d9 ProdID=276c Rev=04.04
> > S: Manufacturer=OPPO
> > S: Product=SDM660-MTP _SN:09C6BCA7
> > S: SerialNumber=beb2c403
> > C: #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=500mA
> > I: If#=0x0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30
> > 
> > Reported-by: Yan Xinyu <sdlyyxy@bupt.edu.cn>
> > Cc: Johan Hovold <johan@kernel.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> > drivers/usb/serial/usb-serial-simple.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/serial/usb-serial-simple.c b/drivers/usb/serial/usb-serial-simple.c
> > index 4c6747889a19..eb832b94aa3a 100644
> > --- a/drivers/usb/serial/usb-serial-simple.c
> > +++ b/drivers/usb/serial/usb-serial-simple.c
> > @@ -60,7 +60,9 @@ DEVICE(flashloader, FLASHLOADER_IDS);
> > 	{ USB_VENDOR_AND_INTERFACE_INFO(0x18d1,			\
> > 					USB_CLASS_VENDOR_SPEC,	\
> > 					0x50,			\
> > -					0x01) }
> > +					0x01) },		\
> > +	{ USB_DEVICE_AND_INTERFACE_INFO(0x22d9, 0x276c,		\
> > +					0xff, 0xff, 0x30) }
> > DEVICE(google, GOOGLE_IDS);
> > 
> > /* Libtransistor USB console */
> > -- 
> > 2.37.1
> Tested-by: Yan Xinyu <sdlyyxy@bupt.edu.cn>

While this may work sufficiently well for real low-volume diag traffic I'd
expect a significant percentage of diag messages to be lost in practice
with the usb-serial-simple driver.

According to the usb-devices output this looks like the Qualcomm USB gadget
in the DIAG + ADB composition to me.

Since the option driver uses the usb-wwan framework my suggestion would be
for the original patch to be applied instead similar to what has been done
e.g. for the Quectel RM500Q diag port.

Regards,
Reinhard