Werner Almesberger 42483d67b4 atusb/fw/: added improved support for interrupt synchronization ... At an interrupt barrier, the host must be able to ensure that no interrupt generated before reaching the barrier is still pending and will be delivered after crossing the barrier. For this, we introduce the following concept: - interrupts have a serial number. This number is sent to the host on EP 1 (currently bulk) to signal the interrupt, instead of the zero byte we used previously. - the new request ATUSB_SPI_WRITE2_SYNC returns the interrupt serial number from after the register write (the register write itself is the interrupt barrier). - the host can now check if the serial indicated from bulk and the serial from ATUSB_SPI_WRITE2_SYNC are the same. If yes, interrupts are synchronized. If not, it has to wait for the interrupt to be signaled on EP 1. We should also consider the case that the interrupt serial has gotten ahead of ATUSB_SPI_WRITE2_SYNC. But that seems to happen rarely. In any case, it's something for the host driver to worry about, not for the firmware. - board.h (irq_serial), board_app.c (irq_serial, INT0_vect): count the interrupt serial number and return it when signaling the interrupt - include/atusb/ep0.h (ATUSB_SPI_WRITE2_SYNC), ep0.c (my_setup): new request ATUSB_SPI_WRITE2_SYNC that does a register write, then returns the interrupt serial		2011-07-07 15:51:07 -03:00
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ep0.h	atusb/fw/: added improved support for interrupt synchronization	2011-07-07 15:51:07 -03:00
usb-ids.h	The Great ATSPI Renaming, part 10: more title comment fixes	2010-11-11 10:47:39 -03:00