Hello Guenter, thank you for your quick answer. 2014-08-21 15:25 GMT+02:00 Guenter Roeck <linux@xxxxxxxxxxxx>: > On Thu, Aug 21, 2014 at 09:29:56AM +0200, Johannes Pointner wrote: >> Hello, >> >> I found out that since this patch https://lkml.org/lkml/2014/6/11/201, >> which fixes the return values in this function, the ntc_thermistor >> driver isn't working anymore for me. >> The problem is that before the driver asked for probe deferral because >> the adc driver isn't loaded at this point and now the probe fails in >> the function iio_channel_get_sys and returns -ENODEV. >> My question is: Who is in this case responsible to request a deferral? >> The driver or the subsystem? >> > Unless I am missing something, iio_get_channel() should request probe deferral. > There is no other way for the driver to know that the adc driver is not loaded > yet. Yes, I missed that. In the function __of_iio_channel_get the subsystem returns a -EPROBE_DEFER. > > The problem here may be that the devicetree entry for the ntc_thermistor driver > may not be correct. The above referenced patch fixes a bug in that area, and > devicetree data is now better validated. > But the problem is, that this statement: if (np && !of_get_property(np, "io-channel-ranges", NULL)) return NULL; overrides the -EPROBE_DEFER. Before the fix there was a break statement and the -EPROBE_DEFER was returned. Do I have made a mistake in the devicetree if I put the ntc declaration directly under the root node? > Guenter Thanks in advance! -- 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
