Re: [PATCH] ARM: dts: at91: Reenable UART TX pull-ups

From: Alexandre Belloni
Date: Tue Dec 10 2019 - 05:57:32 EST


On 03/12/2019 15:21:47+0100, Ingo van Lil wrote:
> Pull-ups for SAM9 UART/USART TX lines were disabled in a previous
> commit. However, several chips in the SAM9 family require pull-ups to
> prevent the TX lines from falling (and causing an endless break
> condition) when the transceiver is disabled.
>
> From the SAM9G20 datasheet, 32.5.1: "To prevent the TXD line from
> falling when the USART is disabled, the use of an internal pull up
> is mandatory.". This commit reenables the pull-ups for all chips having
> that sentence in their datasheets.
>
> Fixes: 5e04822f7db5 ("ARM: dts: at91: fixes uart pinctrl, set pullup on rx, clear pullup on tx")
> Signed-off-by: Ingo van Lil <inguin@xxxxxx>
> Cc: Peter Rosin <peda@xxxxxxxxxx>
> ---
> arch/arm/boot/dts/at91sam9260.dtsi | 12 ++++++------
> arch/arm/boot/dts/at91sam9261.dtsi | 6 +++---
> arch/arm/boot/dts/at91sam9263.dtsi | 6 +++---
> arch/arm/boot/dts/at91sam9g45.dtsi | 8 ++++----
> arch/arm/boot/dts/at91sam9rl.dtsi | 8 ++++----
> 5 files changed, 20 insertions(+), 20 deletions(-)
>
Applied, thanks.

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com