• Damien George's avatar
    stmhal: Protect SD card DMA transactions against USB MSC contention. · f4c17378
    Damien George authored
    Consider the following scenario: SD card is being read by pyboard; USB
    irq comes in for MSC read request; SD card needs to be read from within
    USB irq while SD read is already ongoing.  Such contention needs to be
    This patch provides a simple solution, to raise the irq priority above
    that of the USB irq during SD DMA transfers.  Pyboard and PC can now
    read from the SD card at the same time (well, reads are interleaved).