Messages in this thread | | | Date | Thu, 16 May 2019 17:02:52 +0200 | From | Maxime Ripard <> | Subject | Re: [PATCH 2/3] thermal: sun50i: add thermal driver for h6 |
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Hi,
On Sun, May 12, 2019 at 11:41:28PM +0200, Ondřej Jirman wrote: > > > +static int tsens_get_temp(void *data, int *temp) > > > +{ > > > + struct tsensor *s = data; > > > + struct tsens_device *tmdev = s->tmdev; > > > + int val; > > > + > > > + regmap_read(tmdev->regmap, tmdev->chip->temp_data_base + > > > + 0x4 * s->id, &val); > > > + > > > + if (unlikely(val == 0)) > > > + return -EBUSY; > > > > I'm not sure why a val equals to 0 would be associated with EBUSY? > > Thermal zone driver can (will) call get_temp before we got the > first interrupt and the thermal data. In that case val will be 0. > > Resulting in: > > (val + offset) * scale = (-2794) * -67 = 187198 > > 187°C and immediate shutdown during boot - based on cirtical > temperature being reached. > > Busy here means, get_temp does not yet have data. Thermal zone > driver just reports any error to dmesg output.
Ah, that makes sense.
I guess if we're switching to an interrupt-based driver, then we can just use a waitqueue, or is get_temp supposed to be atomic?
Maxime
-- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com [unhandled content-type:application/pgp-signature] | |