Re: [PATCH 5.10 491/663] USB: serial: option: update interface mapping for ZTE P685M

[Lech Perczak]

Hi,

On 2021-03-01 at 17:12, Greg Kroah-Hartman wrote:
> From: Lech Perczak <lech.perczak@xxxxxxxxx>
>
> commit 6420a569504e212d618d4a4736e2c59ed80a8478 upstream.
>
> This patch prepares for qmi_wwan driver support for the device.
> Previously "option" driver mapped itself to interfaces 0 and 3 (matching
> ff/ff/ff), while interface 3 is in fact a QMI port.
> Interfaces 1 and 2 (matching ff/00/00) expose AT commands,
> and weren't supported previously at all.
> Without this patch, a possible conflict would exist if device ID was
> added to qmi_wwan driver for interface 3.
>
> Update and simplify device ID to match interfaces 0-2 directly,
> to expose QCDM (0), PCUI (1), and modem (2) ports and avoid conflict
> with QMI (3), and ADB (4).
>
> The modem is used inside ZTE MF283+ router and carriers identify it as
> such.
> Interface mapping is:
> 0: QCDM, 1: AT (PCUI), 2: AT (Modem), 3: QMI, 4: ADB
>
> T:  Bus=02 Lev=02 Prnt=02 Port=05 Cnt=01 Dev#=  3 Spd=480  MxCh= 0
> D:  Ver= 2.01 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
> P:  Vendor=19d2 ProdID=1275 Rev=f0.00
> S:  Manufacturer=ZTE,Incorporated
> S:  Product=ZTE Technologies MSM
> S:  SerialNumber=P685M510ZTED0000CP&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&0
> C:* #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=500mA
> I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
> E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> I:* If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
> E:  Ad=83(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
> E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
> E:  Ad=85(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
> E:  Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
> E:  Ad=87(I) Atr=03(Int.) MxPS=   8 Ivl=32ms
> E:  Ad=86(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=04(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> I:* If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none)
> E:  Ad=88(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E:  Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
>
> Cc: Johan Hovold <johan@xxxxxxxxxx>
> Cc: Bjørn Mork <bjorn@xxxxxxx>
> Signed-off-by: Lech Perczak <lech.perczak@xxxxxxxxx>
> Link: https://lore.kernel.org/r/20210207005443.12936-1-lech.perczak@xxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>   drivers/usb/serial/option.c |    3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/drivers/usb/serial/option.c
> +++ b/drivers/usb/serial/option.c
> @@ -1569,7 +1569,8 @@ static const struct usb_device_id option
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1272, 0xff, 0xff, 0xff) },
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1273, 0xff, 0xff, 0xff) },
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1274, 0xff, 0xff, 0xff) },
> -	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1275, 0xff, 0xff, 0xff) },
> +	{ USB_DEVICE(ZTE_VENDOR_ID, 0x1275),	/* ZTE P685M */
> +	  .driver_info = RSVD(3) | RSVD(4) },
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1276, 0xff, 0xff, 0xff) },
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1277, 0xff, 0xff, 0xff) },
>   	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1278, 0xff, 0xff, 0xff) },
If this patch is selected, then 88eee9b7b42e69fb622ddb3ff6f37e8e4347f5b2 
("net: usb: qmi_wwan: support ZTE P685M modem")
should probably be selected, too, or both be dropped.
This patch frees up an interface to be claimed by qmi_wwan driver by the 
mentioned patch.
The mentioned patch only adds a device ID to qmi_wwan driver.

Regarding version, I think that backporting to 5.4.y and later is 
enough, as OpenWrt,
from which both patches originate, is currently on 5.4.y on the target 
requiring them, and will move to 5.10.y soon.
Backporting this would certainly make OpenWrt folks happy for two 
backports fewer, however I don't insist on it.

--
With kind regards,
Lech Perczak