Hello esteemed linux-usb folks, While I am trying to get a little quirk for my custom hardware device added to the ftdi_sio driver, I noticed an inconsistency between use of interface->altsetting vs. interface->cur_altsetting in the existing driver code. Specifically: * ftdi_determine_type() function uses this construct to get the number of the interface it is operating on: inter = serial->interface->altsetting->desc.bInterfaceNumber; * ftdi_set_max_packet_size() uses interface->cur_altsetting to get to desc.bNumEndpoints and endpoint[i].desc * The JTAG cleanup patch which Johan just applied uses intf->cur_altsetting->desc.bInterfaceNumber So which is the right one to use, intf->altsetting or intf->cur_altsetting? The comments in include/linux/usb.h say that the altsetting member points to an array of struct usb_host_interface stored in no particular order, so using that pointer in ftdi_determine_type() seems wrong - but then I am a total novice in this area, hence I am hoping that someone more knowledgeable could confirm. The most recent version of my DUART28C quirk adding patch uses serial->interface->altsetting, copied from ftdi_determine_type() - should I change my proposed patch to use cur_altsetting instead? Should I also make a patch to ftdi_determine_type() changing it to use cur_altsetting as well? TIA, Mychaela she/her/hers
