[PATCH net-next 1/1] net: usb: qmi_wwan: add default rx_urb_size

[Daniele Palmas <dnlplm@gmail.com>]

Add default rx_urb_size to support QMAP download data aggregation
without needing additional setup steps in userspace.

The value chosen is the current highest one seen in available modems.

The patch has the side-effect of fixing a babble issue in raw-ip mode
reported by multiple users.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
---
Resending with mailing lists added: sorry for the noise.

Hi Bjørn and all,

this patch tries to address the issue reported in the following threads

https://www.spinics.net/lists/netdev/msg635944.html
https://www.spinics.net/lists/linux-usb/msg198846.html
https://www.spinics.net/lists/linux-usb/msg198025.html

so I'm adding the people involved, maybe you can give it a try to
double check if this is good for you.

On my side, I performed tests with different QC chipsets without
experiencing problems.

Thanks,
Daniele
---
 drivers/net/usb/qmi_wwan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 07c42c0719f5..92d568f982b6 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -815,6 +815,10 @@ static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
 	}
 	dev->net->netdev_ops = &qmi_wwan_netdev_ops;
 	dev->net->sysfs_groups[0] = &qmi_wwan_sysfs_attr_group;
+
+	/* Set rx_urb_size to allow QMAP rx data aggregation */
+	dev->rx_urb_size = 32768;
+
 err:
 	return status;
 }
-- 
2.17.1