[PATCH 0/9] tty: xuartps: Fix lock ups

From: Soren Brinkmann
Date: Tue Nov 03 2015 - 19:22:23 EST


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.


SÃren Brinkmann (9):
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

drivers/tty/serial/xilinx_uartps.c | 129 ++++++++++++++++++++++---------------
1 file changed, 78 insertions(+), 51 deletions(-)


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