From 0a9410b981e961a24057dceee54bb5d36309a0c4 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 21 Jul 2021 19:24:52 +0300 Subject: [PATCH] serial: 8250_lpss: Enable DMA on Intel Elkhart Lake PSE UARTs on Intel Elkhart Lake support DMA mode. Enable DMA on these ports. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210721162452.48764-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_lpss.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 4dee8a9..848d81e 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -158,6 +158,16 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { + struct uart_8250_dma *dma = &lpss->data.dma; + struct uart_8250_port *up = up_to_u8250p(port); + + /* + * This simply makes the checks in the 8250_port to try the DMA + * channel request which in turn uses the magic of ACPI tables + * parsing (see drivers/dma/acpi-dma.c for the details) and + * matching with the registered General Purpose DMA controllers. + */ + up->dma = dma; return 0; } -- 2.7.4