> To make it clear: Even aside from the buffer in 2.6's pl2303.c, there's > a race: An in-flight write URB can fill all hardware buffers, making > unsafe what previously appeared to be a safe write. I think it's > essential to delay submission of the URB on a stop-transmit condition.
Hardware flow control *is* a race, and always will be. The remote end has a delay in signalling 'stop' there is a propogation delay and a response delay. This is why most implementations assert stop a bit *before* they run out. Given the size of transfers and the internal buffering one would hope the USB devices do their own flow control if told to properly. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/