While you're fixing this, there's a bug in samples/vfio-mdev/mtty.c: u8 ier = mdev_state->s[index].uart_reg[UART_IER]; *buf = 0; mutex_lock(&mdev_state->rxtx_lock); /* Interrupt priority 1: Parity, overrun, framing or break */ if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun) *buf |= UART_IIR_RLSI; /* Interrupt priority 2: Fifo trigger level reached */ if ((ier & UART_IER_RDI) && (mdev_state->s[index].rxtx.count == mdev_state->s[index].intr_trigger_level)) *buf |= UART_IIR_RDI; /* Interrupt priotiry 3: transmitter holding register empty */ if ((ier & UART_IER_THRI) && (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail)) *buf |= UART_IIR_THRI; /* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD */ if ((ier & UART_IER_MSI) && (mdev_state->s[index].uart_reg[UART_MCR] & (UART_MCR_RTS | UART_MCR_DTR))) *buf |= UART_IIR_MSI; /* bit0: 0=> interrupt pending, 1=> no interrupt is pending */ if (*buf == 0) *buf = UART_IIR_NO_INT; It's treating the UART_IIR_* fields as a bitmask which is bad enough, but in the "Interrupt priority 4" case, UART_IIR_MSI is zero, so "*buf |= UART_IIR_MSI" is a no-op. And in the case where the modem status interrupt is the only thing set, *buf will be 0, and UART_IIR_NO_INT gets set erroneously. So this is another example of the bug of trying to treat the UART_IIR_* fields as a bitmask.... Yes, it's only sample code, but best fix it now before it gets copied elsewhere and metastisizes. :-) - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
