Hi,
On 10/17/2012 01:29 PM, Gerd Hoffmann wrote:
Hi,
+ /*
+ * Process / cancel combined packets, called from
+ * usb_ep_combine_input_packets() / usb_combined_packet_cancel().
+ * Only called for devices which call these functions themselves.
+ */
+ int (*handle_combined_data)(USBDevice *dev, USBPacket *p);
+ void (*cancel_combined_packet)(USBDevice *dev, USBPacket *p);
Do we really need these?
For handle_combined_data, yes, as usb_ep_combine_input_packets can
cause multiple packets to get submitted, since if a combined packet
ends with a packet, which does not have its short_not_ok flag set,
another packet can be safely pipelined after it. This is not
useful for usb mass storage, but very usefull for usb serial
port converters.
I actually first did not have cancel_combined_packet :) Instead
I had usb_combined_packet_cancel() return a boolean indicating
if it had handled the cancel, or if the caller (which would be
a device's cancel method) needs to handle the cancel itself.
I personally find the cancel_combined_packet callback somewhat
cleaner, esp. since with the return boolean method,
after calling usb_combined_packet_cancel(p) p->combined will be
NULL, so if the device's cancel method needs access to p->combined
to deal with combined packets, things get more difficult.
But if you prefer getting rid of the callback we can do that.
I think it isn't much work for the callers to
do that themself. Saves them providing a callback. And makes the code
flow easier to follow by removing a pointless indirection.
For handle_combined_data we probably must make
usb_ep_combine_input_packets return a status code.
Regards,
Hans
