linux-imx

spi: qup: fix PIO/DMA transfers.

- DMA/PIO:
  If an error IRQ occurred during PIO or DMA mode make sure to log it so
on completion the transfer can be marked as an error.

- PIO:
  Do not complete a transaction until all data has been transferred or
an error IRQ was flagged.

1) If there was no error IRQ, ignore the done flag IRQ
(QUP_OP_MAX_INPUT_DONE_FLAG) until all data for the transfer has been
processed: not doing so risks completing the transfer returning
uninitialized data in the buffers.

2) Under stress testing we have identified the need to
protect read/write operations against spurious IN/OUT service events.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>