Hi John, On 01/22/2016 02:27 AM, John Ogness wrote: > serial8250_rx_chars() must be called from interrupt context and with > the port lock held. The port lock is released temporarily within that > function to call tty_flip_buffer_push(). However, there may be other > drivers that need to synchronize the tty_flip_buffer_push() call within > serial8250_rx_chars() with other contexts. Since the port lock cannot > be used for this synchronization, an optional spinlock argument is added. > If non-NULL, this will be locked during the tty_flip_buffer_push() call. I removed the port lock drop-claim in serial8250_rx_chars in patch "serial: 8250: Remove low_latency workaround" (Greg has this patch in his inbox but not in next because of the merge window). IOW, you can drop this patch. Regards, Peter Hurley -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html