On Fri, Oct 26, 2012 at 7:19 AM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote: > So we only need to check this in serial8250_handle_irq when IIR indicates > a data timeout interrupt ? > > Can we do > > if ((iir & 0x0F) == 0x0C) { > /* Expensive RDI check */ > } > > > > Alan Checking data timeout interrupt is only for "too much work for irq" problem. There is another console freeze problem which is caused by reading receive FIFO when there is no RDI interrupt, such as during THRI transmit interrupt, so no timeout interrupt. This time one has to check two both IIR and LSR. After all these checking, it becomes the original patch anyway. I am posting another simpler revision to exclude timer handler from this workaround, and make this workaround default off and inline. -- 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