Configure DMA to use 16B burst size with Elkhart Lake. This makes the bus use more efficient and works around an issue which occurs with the previously used 1B.

Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: stable@vger.kernel.org # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu wentong.wu@intel.com Co-developed-by: Srikanth Thokala srikanth.thokala@intel.com Signed-off-by: Srikanth Thokala srikanth.thokala@intel.com Co-developed-by: Aman Kumar aman.kumar@intel.com Signed-off-by: Aman Kumar aman.kumar@intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com

--- I know the list of Co-dev-bys & Sob seems a bit odd for a oneliner. The reason is that I cleaned up this from a more complex patch using the earlier change that I authored myself so only this oneliner remained in this patch. --- drivers/tty/serial/8250/8250_lpss.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index ed281445a97d..e0b4e1446eac 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -174,6 +174,8 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) */ up->dma = dma;

+ lpss->dma_maxburst = 16; + port->set_termios = dw8250_do_set_termios;

return 0;