Re: [PATCH] ARM: at91/dt: pullup dbgu rx instead of tx

From	Peter Rosin <peda@lysator.liu.se>
Newsgroups	linux.kernel
Subject	Re: [PATCH] ARM: at91/dt: pullup dbgu rx instead of tx
Date	2015-09-24 17:30 +0200
Message-ID	<qcgD7-70f-5@gated-at.bofh.it> (permalink)
References	<qcg0p-61m-1@gated-at.bofh.it> <qcg0q-61m-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 2015-09-24 16:47, Alexandre Belloni wrote:
> Hi Peter,
> 
> Thanks for the patch but you actually got beaten by Sylvain:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-September/368426.html

Ok, great!

I just noticed that other ports have the same problem in sama5d3.dtsi. E.g.

	uart1 {
		pinctrl_uart1: uart1-0 {
			atmel,pins =
				<AT91_PIOA 30 AT91_PERIPH_B AT91_PINCTRL_NONE   /* conflicts with TWD0, ISI_VSYNC */
				 AT91_PIOA 31 AT91_PERIPH_B AT91_PINCTRL_PULL_UP>;      /* conflicts with TWCK0, ISI_HSYNC */
		};
	};

Given that the original bug I found spread all over the map, it seems
like someone was confused when the pull-ups were originally added.
Someone (else?) at Atmel needs to audit this so that pull-ups are
added on the rx-pins instead of the tx-pins.

Cheers,
Peter

> On 24/09/2015 at 16:44:15 +0200, Peter Rosin wrote :
>> From: Peter Rosin <peda@axentia.se>
>>
>> It seems pointless to pullup the tx line, but there is value in pulling
>> up the rx line.
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>>  arch/arm/boot/dts/sama5d3.dtsi |    4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/sama5d3.dtsi b/arch/arm/boot/dts/sama5d3.dtsi
>> index 9e2444b07bce..304a40c5552a 100644
>> --- a/arch/arm/boot/dts/sama5d3.dtsi
>> +++ b/arch/arm/boot/dts/sama5d3.dtsi
>> @@ -545,8 +545,8 @@
>>  				dbgu {
>>  					pinctrl_dbgu: dbgu-0 {
>>  						atmel,pins =
>> -							<AT91_PIOB 30 AT91_PERIPH_A AT91_PINCTRL_NONE	/* PB30 periph A */
>> -							 AT91_PIOB 31 AT91_PERIPH_A AT91_PINCTRL_PULL_UP>;	/* PB31 periph A with pullup */
>> +							<AT91_PIOB 30 AT91_PERIPH_A AT91_PINCTRL_PULL_UP	/* PB30 periph A with pullup */
>> +							 AT91_PIOB 31 AT91_PERIPH_A AT91_PINCTRL_NONE>;	/* PB31 periph A */
>>  					};
>>  				};
>>  
>> -- 
>> 1.7.10.4
>>
> 

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Thread

Re: [PATCH] ARM: at91/dt: pullup dbgu rx instead of tx Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2015-09-24 16:50 +0200
  Re: [PATCH] ARM: at91/dt: pullup dbgu rx instead of tx Peter Rosin <peda@lysator.liu.se> - 2015-09-24 17:30 +0200
    Re: [PATCH] ARM: at91/dt: pullup dbgu rx instead of tx Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2015-09-24 18:30 +0200

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