Usb to can driver

["Max S." <max@schneidersoft.net>]

Some more questions regarding usb to can driver.

When CAN_CTRLMODE_LISTENONLY is set; why does the start_xmit function still get called?
Its not really a problem, I'm just wondering why when a socket is listen only, it still attempts to TX...

My firmware implements LOOPBACK by default. That is all frames sent by
the can hardware are also returned over usb. I use this effect to call
can_get_echo_skb() during bulk in. To support LOOPBACK mode as per
socketcan; should i also call netif_rx() durring bulk in if CAN_CTRLMODE_LOOPBACK is
set?

I am currently using:
struct __packed gs_host_frame {
	u32 echo_id;
	u32 can_id;

	u32 can_dlc;
	u32 channel;
	u32 flags;

	u8 data[8];
};
as the data format between host/device. Using u32 for
memory alignment as suggested. Is there any way I can reduce the amount
of wasted space? At 1Mhz std rtr frame is ~21K frames/s. For two
channels both ways that's 21x2x2=84k frames/s. At 28 bytes per frame
that's 84x28x8=18.816Mbit/s too much for a USB full-speed device. I
want to reduce gs_host_frame size and get closer to 12Mbit/s.

What is the purpose of enum can_mode and set mode? I see that allot of drivers more or less ignore it.
reacting to only START but not SLEEP or STOP...

Max Schnedier.