Subject: Re: [PATCH] regulator: s2mps11: Remove unused set_voltage_time_sel
To: Mark Brown <broonie@kernel.org>
References: <1460965378-5256-1-git-send-email-k.kozlowski@samsung.com>
 <20160418095713.GO3217@sirena.org.uk>
Cc: Sangbeom Kim <sbkim73@samsung.com>, Liam Girdwood <lgirdwood@gmail.com>,
        linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Message-id: <5714B8C4.5070207@samsung.com>
Date: Mon, 18 Apr 2016 12:36:52 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.6.0
MIME-version: 1.0
In-reply-to: <20160418095713.GO3217@sirena.org.uk>
Content-type: text/plain; charset=windows-1252
Content-transfer-encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 985
Lines: 23

On 04/18/2016 11:57 AM, Mark Brown wrote:
> On Mon, Apr 18, 2016 at 09:42:58AM +0200, Krzysztof Kozlowski wrote:
> 
>> On S2MPS11 and S2MPS14 devices the default implementation of
>> set_voltage_time_sel() for LDO regulators was not doing anything useful
>> because users did not provide ramp delay in Device Tree so the
>> set_voltage_time_sel() exited with status 0. This could be seen in
>> dmesg, e.g. on Odroid XU4:
> 
> That's not the bug, the bug is that the driver is providing the
> operation without providing a non-zero value for it.  The device tree
> configuration is to override what the driver is doing.

So your recommendation would be to set the ramp_delay value in
regulator_desc structure?

The problem is that value of 30 mv/us in datasheet looks untrustworthy
(copied from other pages) and vendor kernel (which should be a
reference) uses 12 mv/us. Anyway setting any value greater than 0 seems
like better idea than just sticking to 0...

Best regards,
Krzysztof