Hi all,
Here, my customer needs the DMA support in the UART driver in the Linux. And it is very important for us to win the case? So could you help to share me whether there is the driver patch support for it.
Thanks!
Yaoming
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Hi all,
Here, my customer needs the DMA support in the UART driver in the Linux. And it is very important for us to win the case? So could you help to share me whether there is the driver patch support for it.
Thanks!
Yaoming
Yaoming,
Looking at the AM335x device tree (arch/arm/boot/dts/am33xx.dtsi) in the Linux Processor SDK v2.0.1.7 there are DMAs associated with uart0, uart1, and uart2. Also looking at the UART driver (drivers/tty/serial/8250/8250_omap.c) there is a CONFIG_SERIAL_8250_DMA option to enable the DMAs. This configuration can be found in menuconfig under 'Device Drivers->Character devices->Serial drivers->DMA support for 16550 compatible UART controllers'.
I am currently ramping up on supporting UART on the Sitara devices so I am also checking with the UART Linux developers on this question. I will let you know what I find out from those discussions.
Jason Reeder
Jason,
The customer has no requirement on the h/w flow control, so is it still OK to enable the DMA there?
The date for the next release is too late to win this case. I hope we can fix the issue with in 2 weeks.
Thanks!
Yaoming