Hi Reinhard,
> On Jul 16, 2022, at 20:13, Reinhard Speyerer <rspmn@xxxxxxxx> wrote:
>
> On Fri, Jul 15, 2022 at 10:59:13PM +0800, sdlyyxy wrote:
>>
>>> On Jul 15, 2022, at 22:24, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxx>
>>> Cc: Johan Hovold <johan@xxxxxxxxxx>
>>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>>> ---
>>> 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@xxxxxxxxxxx>
>
> 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
>
I tested the diag port using two userspace programs: QCSuper[1]
and scat[2]. Both option and usb-serial-simple drivers generate
similar output, so I cannot comfirm diag message loss. Do you
have any test method suggestions to generate high-volume diag
traffic and detect message loss?
[1] https://github.com/P1sec/QCSuper
[2] https://github.com/fgsect/scat
Thanks,
sdlyyxy
