From: Marek Vasut <marex@denx.de>
To: Yann GAUTIER <yann.gautier@st.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Cc: Alexandre TORGUE <alexandre.torgue@st.com>,
"a.fatoum@pengutronix.de" <a.fatoum@pengutronix.de>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Patrick DELAUNAY <patrick.delaunay@st.com>,
"linux-stm32@st-md-mailman.stormreply.com"
<linux-stm32@st-md-mailman.stormreply.com>
Subject: Re: [Linux-stm32] [PATCH] ARM: dts: stm32: Consistently enable internal pull-ups for SD bus
Date: Wed, 14 Oct 2020 16:55:41 +0200 [thread overview]
Message-ID: <808c1e29-a96f-f3f4-7e5d-7ba2dfed4142@denx.de> (raw)
In-Reply-To: <99663cc5-f897-8233-518b-1a485a2e15b6@st.com>
On 10/14/20 4:52 PM, Yann GAUTIER wrote:
>
>
> On 10/14/20 3:30 PM, Marek Vasut wrote:
>> On 10/14/20 3:26 PM, Yann GAUTIER wrote:
>> [...]
>>>> diff --git a/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi b/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
>>>> index b2d19583450c..73d9a5b7f5ba 100644
>>>> --- a/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
>>>> +++ b/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
>>>> @@ -1291,13 +1291,13 @@ pins1 {
>>>> <STM32_PINMUX('D', 2, AF12)>; /* SDMMC1_CMD */
>>>> slew-rate = <1>;
>>>> drive-push-pull;
>>>> - bias-disable;
>>>> + bias-pull-up;
>>> Hi Marek,
>>
>> Hi,
>>
>>> This pin config is used by ST board, where we have a level shifter.
>>> This shouldn't be changed. We discussed this with Alex, and a new group
>>> should be added in this case.
>>
>> Is it a problem if we enable the pulls up unconditionally with the level
>> shifter present, to make the properties of the SD bus consistent ?
>>
> The risk of having 2 parallel pull-ups is that the resulting value could
> be below the lower acceptable value for SD. I'll check if that can occur.
That's a good idea, thank you!
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next prev parent reply other threads:[~2020-10-14 14:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 21:08 [PATCH] ARM: dts: stm32: Consistently enable internal pull-ups for SD bus Marek Vasut
2020-10-14 13:26 ` [Linux-stm32] " Yann GAUTIER
2020-10-14 13:30 ` Marek Vasut
2020-10-14 14:52 ` Yann GAUTIER
2020-10-14 14:55 ` Marek Vasut [this message]
2020-10-15 12:44 ` Ahmad Fatoum
2020-10-15 12:52 ` Marek Vasut
2020-10-15 13:18 ` Ahmad Fatoum
2020-10-15 13:40 ` Marek Vasut
2020-10-15 13:47 ` Ahmad Fatoum
2020-10-15 15:51 ` Alexandre Torgue
2020-10-15 17:43 ` Marek Vasut
2020-10-16 6:19 ` Ahmad Fatoum
2020-10-16 11:02 ` Marek Vasut
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