[PATCH v2 00/10] tty: xuartps: Fix lock ups

[Soren Brinkmann]

Hi,

this is v2, hopefully without any build issues. The changes are the same
as before, just the warning reported by kbuild test robot about unused
variables have been fixed. And, I added one more patch with some
cleanup/refactoring.

I recently found my system locking up under some conditions. I dug
through the code a bit and the result is this collections of various
changes. Some of it may not be required and has just been created out of
half-baked theories and re-reading the documentation. The actual failing
scenarios seem to be:
 - RX IRQ conditions are handled while the receiver is disabled, leaving
   the driver in an infinite loop
 - console_put_char seems to be interrupted by uart_shutdown disabling
   the transmitter while/just before printing

I.e. overall I tried to serialize all operations using the port lock to
avoid such interaction.

	Sören

Sören Brinkmann (10):
  tty: xuartps: Beautify read-modify writes
  tty: xuartps: Use spinlock to serialize HW access
  tty: xuartps: Always enable transmitter in start_tx
  tty: xuartps: Clear interrupt status register in shutdown
  tty: xuartps: Improve startup function
  tty: xuartps: Keep lock for whole ISR
  tty: xuartps: Acquire port lock for shutdown
  tty: xuartps: Move RX path into helper function
  tty: xuartps: Only handle RX IRQs when RX is enabled
  tty: xuartps: Cleanup: Reformat if-else

 drivers/tty/serial/xilinx_uartps.c | 247 ++++++++++++++++++++-----------------
 1 file changed, 136 insertions(+), 111 deletions(-)

-- 
2.6.2.3.ga463a5b