On Wed, 2016-11-23 at 13:32 -0800, Guenter Roeck wrote: > On Wed, Nov 23, 2016 at 10:07:11PM +0100, Bastien Nocera wrote: > > On Wed, 2016-11-23 at 18:38 +0100, Jean Delvare wrote: > > > On mer., 2016-11-23 at 18:21 +0100, Bastien Nocera wrote: > > > > Hey, > > > > > > > > I did some work on iio-sensor-proxy[1] those past couple of > > > > days, and > > > > tested it on a MacBook Pro. > > > > > > > > Before that, I had written a (user-space) driver to access the > > > > hwmon > > > > driver's "light" value, so I was a bit surprised when I saw > > > > that iio- > > > > sensor-proxy was accessing the light sensor through acpi-als's > > > > IIO driver > > > > instead of through the hwmon driver. > > > > > > > > I looked through the hwmon, iio and applesmc.c logs, and > > > > couldn't find any > > > > information about how the move from one to the other. Does > > > > anyone know? > > > > > > > > I'm asking because the applesmc.c hwmon driver is the only one > > > > with > > > > support for the "light" property, and if that's not used > > > > anymore, I might > > > > as well remove that code now (or schedule to remove it). > > > > > > Light sensors are out of scope of hwmon, they have nothing to do > > > with > > > hardware monitoring. > > > > Why is there still code in applesmc.c to handle the "light" sysfs > > property > > then? > > > > Interesting question. Because no one bothered enough to remove it ? > Because > other applications may still use it ? Because old apple hardware may > not > support ACPI0008 ? There can be many reasons. All good reasons. The lack of ACPI0008 support would be the main reason for me to keep the hwmon driver support in iio-sensor-proxy. > If the question is why it is there in the first place, please keep in > mind that > the driver is quite old. "For historic reasons" may be the best > answer to that > question. Oh, I know it's old, I've used it on 2 different Intel-based MacBook Airs ;) > > Also, this doesn't answer my question as to when this switch > > happened. I > > don't care one way or the other, but knowing when the switch was > > made can > > allow me to prepare the hwmon driver in iio-sensor-proxy for > > removal. > > > > From kernel perspective, it may have been more or less automatic with > the addition of acpi-als support to iio. Either case, isn't it up to > iio-sensor-proxy to decide which kernel ABI it wants to use ? In this case, we don't have a choice, the device is getting bound to the acpi-als driver and hwmon just doesn't have the light support. In any case, iio-sensor-proxy only binds to a single sensor of each type, so we're good here. I'll leave the hwmon support for older Intel Macs in. Cheers -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
