[0/8] serial: imx: work-around for hardware RX flood, and then isr improvements

Message

Sergey Organov Jan. 13, 2023, 6:43 p.m. UTC

These series contain a work-around for hardware RX flood in first 2
commits, and then further cleanups and optimizations of the receive IRQ
handler.

WARNING: the flood fix is extensively tested with older version of the
kernel with DMA turned off. The DMA path is tested only a bit, as DMA has
receive problems on my kernel version.

Sergey Organov (8):
  serial: imx: factor-out common code to imx_uart_soft_reset()
  serial: imx: work-around for hardware RX flood
  serial: imx: do not sysrq broken chars
  serial: imx: do not break from FIFO reading loop prematurely
  serial: imx: remove redundant USR2 read from FIFO reading loop
  serial: imx: stop using USR2 in FIFO reading loop
  serial: imx: use readl() to optimize FIFO reading loop
  serial: imx: refine local variables in rxint()

 drivers/tty/serial/imx.c | 227 ++++++++++++++++++++++++---------------
 1 file changed, 141 insertions(+), 86 deletions(-)