On Tue, 2017-02-07 at 18:09 +0100, Lucas Stach wrote: > Am Dienstag, den 07.02.2017, 17:45 +0100 schrieb Philipp Zabel: > > On Fri, 2017-02-03 at 10:52 -0200, Fabio Estevam wrote: > > > Hi Philipp, > > > > > > On Tue, Jan 3, 2017 at 5:11 PM, Fabio Estevam <festevam@xxxxxxxxx> wrote: > > > > From: Fabio Estevam <fabio.estevam@xxxxxxx> > > > > > > > > Commit deb65870b5d9d ("drm/imx: imx-tve: check the value returned by > > > > regulator_set_voltage()") exposes the following probe issue: > > > > > > > > 63ff0000.tve supply dac not found, using dummy regulator > > > > imx-drm display-subsystem: failed to bind 63ff0000.tve (ops imx_tve_ops): -22 > > > > > > > > When the 'dac' regulator is not passed in the device tree, > > > > devm_regulator_get() will return NULL and when regulator_set_voltage() > > > > is called it returns an error. > > > > > > > > Fix the issue by making the 'dac' regulator optional. > > > > > > > > Fixes: deb65870b5d9d ("drm/imx: imx-tve: check the value returned by regulator_set_voltage()") > > > > Cc: <stable@xxxxxxxxxxxxxxx> # 4.8+ > > > > Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx> > > > > > > Any comments, please? > > > > I've applied this to the fixes branch, since the current device trees > > don't have the regulator set. > > > > Is this really optional, though? It would be better to add the correct > > dac-supply to the device trees. > > > Why does the driver attempt to set the voltage? I guess the voltage is > fixed, even if it is hooked up to a configurable regulator. Good point, I suppose what the driver should really do is warn if the voltage not set correctly? > Shouldn't we just remove the set_voltage call from the driver and make > sure the correct voltage is supplied by board level DT constraints? I think so, yes. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html