[PATCH v2 2/2] ARM: tegra: Add high speed UARTs to Jetson TK1 device tree

[Ralf Ramsauer]

On 01/26/16 20:27, Stephen Warren wrote:
> On 01/26/2016 09:59 AM, Ralf Ramsauer wrote:
>> This patch enables the APB DMA high speed UARTs of the Jetson TK1. So
>> far, they were only enabled in NVidia's official BSP.
>>
>> Those additional UARTs are exposed on the expansion connector J3A2:
>>
>>   UART1:
>>    Pin 41: BR_UART1_TXD
>>    Pin 44: BR_UART1_RXD
>>
>>   UART2:
>>    Pin 65: UART2_RXD
>>    Pin 68: UART2_TXD
>>    Pin 71: UART2_CTS_L
>>    Pin 74: UART2_RTS_L
>
> The series,
> Acked-by: Stephen Warren <swarren at nvidia.com>
>
>
> As an aside, this is perfectly OK, but I wonder why you chose to use
> compatible=nvidia,tegra124-hsuart rather than
> compatible=nvidia,tegra124-uart. The -hsuart driver has had less
> testing upstream, whereas the regular -uart driver is heavily used for
> the main serial console. I assume you tested the new driver when
> enabling the ports:-)
Let me explain it, this is how I found the typos :-)

tegra124.dtsi states:
    /*
     * There are two serial driver i.e. 8250 based simple serial
     * driver and APB DMA based serial driver for higher baudrate
     * and performace. To enable the 8250 based driver, the compatible
     * is "nvidia,tegra124-uart", "nvidia,tegra20-uart" and to enable
     * the APB DMA based serial driver, the compatible is
     * "nvidia,tegra124-hsuart", "nvidia,tegra30-hsuart".
     */

There's nothing written about the upstream stability of the hsuart
driver. So I didn't even try to use the non-hs uart driver. Nevertheless
I successfully tested both additional uarts using the hsuart driver
against 4.5-rc1 and some uart-speaking device.

  Ralf

-- 
Ralf Ramsauer
GPG: 0x8F10049B