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

On Thu, Mar 04, 2021 at 12:58:19AM +0100, Lech Perczak wrote:

Hi,

On 2021-03-01 at 17:12, Greg Kroah-Hartman wrote:

quoted

From: Lech Perczak <redacted>

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@kernel.org>
Cc: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Lech Perczak <redacted>
Link: https://lore.kernel.org/r/20210207005443.12936-1-lech.perczak@gmail.com (local)
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
  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")
probably should be selected, too. 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.

In my opinion, those two should come in pair. Regarding version, I think
that backporting to 5.4.y and later is enough, as OpenWrt,
from which those patches originate is currently on 5.4.y on the target
requiring it, and will move to 5.10.y soon.
Backporting this would certainly make OpenWrt folks happy, however I don't
insist on it.

Now queued up, thanks.

greg k-h