On Thu, Mar 12, 2015 at 11:04:41AM +0000, Russell King - ARM Linux wrote:

On Wed, Mar 04, 2015 at 12:27:34PM +0000, Dave Martin wrote:

quoted

Getting the TX IRQ re-asserted from scratch can be inefficient in
some setups.

This patch avoids clearing the TX IRQ across pl011_shutdown()...
pl011_startup(), so that if the port is closed and reopened, the
IRQ will still work afterwards without having to bootstrap it again.

So if a port is being used as the console, we end up spraying the system
with transmit interrupts?  This can't be right.

Nope, if the port is not open theough serial_core then TXIS remains
asserted but is masked off in IMSC.

This should be  just the same as the way we avoid a screaming TX interrupt
when the port *is* open but the transmitter is idle.


My commit message could have explained that better...

Cheers
---Dave