On Fri, Feb 16, 2018 at 01:00:06AM +0200, Ran Shalit wrote: > Hello, > > I am trying to understand article on reverse engineering usb driver, > published in > http://www.linuxjournal.com/node/7353/print (2004) That article was written a _long_ time ago :( > I have difficulties understanding the input to the function usb_control_msg() > especially the 0x12, 0xc8 numbers. > I could not find them in the article, then tried even in the delcom > datasheet, but did not find it there too. > These numbers refer to __u8 request, __u8 requesttype , value, and > index, but I could not understand how they are figured it out in the > article. > > usb_control_msg(led->udev, > usb_sndctrlpipe(led->udev, 0), > 0x12, <<------- ? > 0xc8, <<------ ? > (0x02 * 0x100) + 0x0a, <------ ? > (0x00 * 0x100) + color, <------ ? > buffer, > 8, > 2 * HZ); I thought I got them from the data sheet for the device, but that was over a decade ago, so I really don't remember, sorry. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
