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From: Mark Brown <broonie@kernel.org>
To: Peter Geis <pgwipeout@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	linux-mmc@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	devicetree@vger.kernel.org
Subject: Re: [BUG] mmc_regulator_set_ocr can't cope with regulator-fixed
Date: Thu, 5 Aug 2021 13:46:50 +0100	[thread overview]
Message-ID: <20210805124650.GM26252@sirena.org.uk> (raw)
In-Reply-To: <CAMdYzYr9PX-9=kkCAfGe8Q0-D+gRo_qCwse8SiGVsmod7fffiA@mail.gmail.com>

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On Thu, Aug 05, 2021 at 07:38:06AM -0400, Peter Geis wrote:

> Also, I've got a possible fix to the dw-mmc issue, the following patch
> changes the behavior to only enable a fixed regulator, not try to set
> the voltage. It's a split between the behavior when vmmc isn't defined
> at all and when its a variable regulator:

One thing to watch out for with this approach is if there's things that
really need a specific voltage to be set then you'll have to stop those
things happening if you've got a voltage regulator that can't deliver a
voltage in the required range.  I don't know if this affects MMC or not,
if it's just a case of being less efficient it's not such an issue.

> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index d333130d1531..b30102980261 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1446,11 +1446,13 @@ static void dw_mci_set_ios(struct mmc_host
> *mmc, struct mmc_ios *ios)
>   switch (ios->power_mode) {
>   case MMC_POWER_UP:
>   if (!IS_ERR(mmc->supply.vmmc)) {
> - ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,

This patch is very whitespace damaged FWIW.

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WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Peter Geis <pgwipeout@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	linux-mmc@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	devicetree@vger.kernel.org
Subject: Re: [BUG] mmc_regulator_set_ocr can't cope with regulator-fixed
Date: Thu, 5 Aug 2021 13:46:50 +0100	[thread overview]
Message-ID: <20210805124650.GM26252@sirena.org.uk> (raw)
In-Reply-To: <CAMdYzYr9PX-9=kkCAfGe8Q0-D+gRo_qCwse8SiGVsmod7fffiA@mail.gmail.com>


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On Thu, Aug 05, 2021 at 07:38:06AM -0400, Peter Geis wrote:

> Also, I've got a possible fix to the dw-mmc issue, the following patch
> changes the behavior to only enable a fixed regulator, not try to set
> the voltage. It's a split between the behavior when vmmc isn't defined
> at all and when its a variable regulator:

One thing to watch out for with this approach is if there's things that
really need a specific voltage to be set then you'll have to stop those
things happening if you've got a voltage regulator that can't deliver a
voltage in the required range.  I don't know if this affects MMC or not,
if it's just a case of being less efficient it's not such an issue.

> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index d333130d1531..b30102980261 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1446,11 +1446,13 @@ static void dw_mci_set_ios(struct mmc_host
> *mmc, struct mmc_ios *ios)
>   switch (ios->power_mode) {
>   case MMC_POWER_UP:
>   if (!IS_ERR(mmc->supply.vmmc)) {
> - ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,

This patch is very whitespace damaged FWIW.

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_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

  reply	other threads:[~2021-08-05 12:47 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20210804143357epcas1p1c67eca591d8bb557c11b8175baaa8550@epcas1p1.samsung.com>
2021-08-04 14:32 ` [BUG] mmc_regulator_set_ocr can't cope with regulator-fixed Peter Geis
2021-08-04 14:32   ` Peter Geis
2021-08-04 16:15   ` Mark Brown
2021-08-04 16:15     ` Mark Brown
2021-08-05 10:00   ` Jaehoon Chung
2021-08-05 10:00     ` Jaehoon Chung
2021-08-05 11:38     ` Peter Geis
2021-08-05 11:38       ` Peter Geis
2021-08-05 12:46       ` Mark Brown [this message]
2021-08-05 12:46         ` Mark Brown
2021-08-05 12:58         ` Peter Geis
2021-08-05 12:58           ` Peter Geis
2021-08-05 13:08           ` Mark Brown
2021-08-05 13:08             ` Mark Brown
2021-08-06  8:14             ` Ravikumar Kattekola
2021-08-06  8:14               ` Ravikumar Kattekola
2021-08-06 10:59               ` Mark Brown
2021-08-06 10:59                 ` Mark Brown

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