From: Chris Ball <cjb@laptop.org>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org,
Kyungmin Park <kyungmin.park@samsung.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Liam Girdwood <lrg@ti.com>
Subject: Re: [PATCH v2] mmc: sdhci: apply voltage range check only for non-fixed regulators
Date: Tue, 13 Nov 2012 08:45:57 -0500 [thread overview]
Message-ID: <87bof1mx9m.fsf@octavius.laptop.org> (raw)
In-Reply-To: <1352813534-6795-1-git-send-email-m.szyprowski@samsung.com> (Marek Szyprowski's message of "Tue, 13 Nov 2012 14:32:14 +0100")
Hi Marek,
On Tue, Nov 13 2012, Marek Szyprowski wrote:
> Fixed regulators cannot change their voltage, so disable all voltage
> range checking for them, otherwise the driver fails to operate with
> fixed regulators. Up to now it worked only by luck, because
> regulator_is_supported_voltage() function returned incorrect values.
> Commit "regulator: fix voltage check in regulator_is_supported_voltage()"
> fixed that function and now additional check is needed for fixed
> regulators.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> drivers/mmc/host/sdhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index c7851c0..6f6534e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2923,7 +2923,7 @@ int sdhci_add_host(struct sdhci_host *host)
> regulator_enable(host->vmmc);
>
> #ifdef CONFIG_REGULATOR
> - if (host->vmmc) {
> + if (host->vmmc && regulator_count_voltages(host->vmmc) > 1) {
> ret = regulator_is_supported_voltage(host->vmmc, 3300000,
> 3300000);
> if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_330)))
Thanks for the longer explanation. I'm still missing something, though;
what's wrong with running the check as it was with the new regulator code?
(I haven't tried it yet.)
#ifdef CONFIG_REGULATOR
if (host->vmmc) {
ret = regulator_is_supported_voltage(host->vmmc, 3300000,
3300000);
if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_330)))
caps[0] &= ~SDHCI_CAN_VDD_330;
ret = regulator_is_supported_voltage(host->vmmc, 3000000,
3000000);
if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_300)))
caps[0] &= ~SDHCI_CAN_VDD_300;
ret = regulator_is_supported_voltage(host->vmmc, 1800000,
1800000);
if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_180)))
caps[0] &= ~SDHCI_CAN_VDD_180;
}
#endif /* CONFIG_REGULATOR */
The point is to remove unsupported voltages, so if someone sets up a
fixed regulator at 3300000, all of the other caps are disabled. Why
wouldn't that work without this change, and how are we supposed to
remove those caps on a fixed regulator after your patchset?
Thanks, sorry if I'm missing something obvious,
- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child
next prev parent reply other threads:[~2012-11-13 13:46 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-13 8:48 [PATCH 0/3] Fix fixed regulators support Marek Szyprowski
2012-11-13 8:48 ` [PATCH 1/3] regulator: fix voltage check in regulator_is_supported_voltage() Marek Szyprowski
2012-11-13 9:01 ` Mark Brown
2012-11-13 8:48 ` [PATCH 2/3] regulator: threat regulators with constant volatage as fixed Marek Szyprowski
2012-11-13 9:00 ` Mark Brown
2012-11-13 9:35 ` [PATCH v2] regulator: treat " Marek Szyprowski
2012-11-13 9:42 ` Mark Brown
2012-11-13 9:49 ` [PATCH v3] " Marek Szyprowski
2012-11-14 2:01 ` Mark Brown
2012-11-20 13:20 ` Marek Szyprowski
2012-11-13 8:48 ` [PATCH 3/3] mmc: sdhci: apply voltage range check only for non-fixed regulators Marek Szyprowski
2012-11-13 12:45 ` Chris Ball
2012-11-13 13:32 ` [PATCH v2] " Marek Szyprowski
2012-11-13 13:45 ` Chris Ball [this message]
2012-11-13 14:09 ` Marek Szyprowski
2012-11-13 14:14 ` Chris Ball
2012-11-13 21:23 ` Philip Rakity
2012-11-20 8:42 ` Marek Szyprowski
2012-11-14 1:10 ` [PATCH 3/3] " Mark Brown
[not found] <25B60CDC2F704E4E9D88FFD52780CB4C060FBEA29A@SC-VEXCH1.marvell.com>
2012-11-14 7:11 ` FW: [PATCH v2] " Kevin Liu
2012-11-14 7:28 ` Mark Brown
2012-11-14 8:36 ` Kevin Liu
2012-11-14 8:41 ` Mark Brown
2012-11-14 8:57 ` Kevin Liu
2012-11-14 9:08 ` Philip Rakity
2012-11-14 12:05 ` Kevin Liu
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