libqmi / Quectel EC21/EC25

[Bjørn Mork]

Sebastian Sjoholm <sebastian.sjoholm at gmail.com> writes:

>> 
>>> Hi,
>>> 
>>> So regarding my issue with Quectel EC21/EC25, I guess most of the times the problem is between the keyboard and the chair, and I guess it was now as well.
>>> 
>>> When I followed the Quectel documentation on Linux integration I left the raw-ip implementation because linux kernel already have raw-ip support in the kernel, however at the end of that chapter was some crucial changes that I of course did not include. So, after included the changes in “qmi_wwan_bind”, it started to work.
>>> 
>>> I have included the diff from my changes and the Linux Kernel 4.7.7.
>>> 
>>> I have only verified EC25, but will soon run EC21 as well.
>>> 
>>> /drivers/net/usb/qmi_wwan.c
>>> 436,451d435
>>> < 
>>> < 	/* Quectel */
>>> < 	if (dev->udev->descriptor.idVendor == cpu_to_le16(0x2C7C)) {
>>> < 		dev_info(&intf->dev, "Quectel EC21&EC25&EC20 R2.0 work on RawIP mode\n");
>>> < 		dev->net->flags |= IFF_NOARP;
>>> < 
>>> < 		usb_control_msg(
>>> < 			interface_to_usbdev(intf),
>>> < 			usb_sndctrlpipe(interface_to_usbdev(intf), 0),
>>> < 			0x22, //USB_CDC_REQ_SET_CONTROL_LINE_STATE
>>> < 			0x21, //USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE
>>> < 			1, //active CDC DTR
>>> < 			intf->cur_altsetting->desc.bInterfaceNumber,
>>> < 			NULL, 0, 100);
>>> < 	}
>> 
>> 
>> I don't understand.  Except for the redundant IFF_NOARP (set in
>> qmi_wwan_netdev_setup), this should be exactly the same as the
>> 
>> 		qmi_wwan_change_dtr(dev, true);
>> 
>> I asked you to try to enable unconditionally.  And that didn't work?
>> 
>
> I did try that, yes, but I got the same timeout error with qmicli, but I will check again, and let you know.
>
> Just to make sure I get it right;
>
> instead of
>
>         if (le16_to_cpu(dev->udev->descriptor.bcdUSB) >= 0x0201) {
>                 qmi_wwan_manage_power(dev, 1);
>                 qmi_wwan_change_dtr(dev, true);
>         }
>
> I will just have
>
>        qmi_wwan_manage_power(dev, 1);
>        qmi_wwan_change_dtr(dev, true);
>
> And of course comment out the changes in “qmi_wwan_bind”.

Yes.  That should have the same effect.  If it doesn't, then there must
be something magic going on.  Could be related to timing/ordering of
course.  Could you generate a context diff (diff -u) of the changes you
have made, so that we can see where that control message is sent?




Bjørn