Re: [PATCH 2/3] thermal: Add Mediatek thermal controller support

[Daniel Kurtz <djkurtz@chromium.org>]

On Mon, Jan 4, 2016 at 10:31 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Mon, Dec 21, 2015 at 12:07:58PM +0800, Daniel Kurtz wrote:
>> Hi Sascha,
>>
>> One nit below that can be fixed up later, or now if you don't plan to
>> spin this driver to
>> address Eduardo's feedback...
>>
>> On Mon, Nov 30, 2015 at 7:42 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
>> > This adds support for the Mediatek thermal controller found on MT8173
>> > and likely other SoCs.
>> > The controller is a bit special. It does not have its own ADC, instead
>> > it controls the on-SoC AUXADC via AHB bus accesses. For this reason
>> > we need the physical address of the AUXADC. Also it controls a mux
>> > using AHB bus accesses, so we need the APMIXEDSYS physical address aswell.
>> >
>> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>
>> [snip]
>>
>> > +static int mtk_thermal_get_calibration_data(struct device *dev, struct mtk_thermal *mt)
>> > +{
>> > +       struct nvmem_cell *cell;
>> > +       u32 *buf;
>> > +       size_t len;
>> > +       int i, ret = 0;
>> > +
>> > +       /* Start with default values */
>> > +       mt->adc_ge = 512;
>> > +       for (i = 0; i < MT8173_NUM_SENSORS; i++)
>> > +               mt->vts[i] = 260;
>> > +       mt->degc_cali = 40;
>> > +       mt->o_slope = 0;
>> > +
>> > +       cell = nvmem_cell_get(dev, "calibration-data");
>> > +       if (IS_ERR(cell)) {
>> > +               if (PTR_ERR(cell) == -EPROBE_DEFER)
>>
>> It is useful to know why the thermal driver is being probe defered, so
>> I suggest here:
>> dev_warn(dev, "Waiting for calibration data.\n");
>
> The problem with that is that this message is not shown once but
> possibly many times and may not even show a problem because in the end
> the device may be probed successfully. In this case the last thing you
> see from the device is "Waiting for calibration data." and get annoyed
> by all this useless noise from the driver.
>
> Of course I agree that this information may be useful in the case you
> wonder why your device doesn't show up...

The solution for this, then, is:
 dev_dbg()