On Fri, 2015-10-23 at 07:43AM +0200, Mike Looijmans wrote: > On 23-10-15 07:31, Mike Looijmans wrote: > >On 22-10-15 18:07, Sören Brinkmann wrote: > >>Hi Mike, > >> > >>On Thu, 2015-10-22 at 01:30PM +0200, Mike Looijmans wrote: > >>>Supplying pinmux configuration for e.g. gpio pins leads to deferred > >>>probes because the pinctrl device is probed much later than gpio. > >>>Move the init call to a much earlier stage so it probes before the > >>>devices that may need it. > >>> > >>>Signed-off-by: Mike Looijmans <mike.looijm...@topic.nl> > >> > >>in general, the change should be OK, but neither on zc702 nor zc706 do I > >>see a difference in respect to deferred probes. With and without the > >>patch I see: > >> root@zynq:~# dmesg | grep -i defer > >> [ 0.097021] zynq-gpio e000a000.gpio: could not find pctldev for node > >>/amba/slcr@f8000000/pinctrl@700/gpio0-default, deferring probe > >> root@zynq:~# > >> > >>If you have a case this patch improves things though, feel free to add my > >>Tested-by: Sören Brinkmann <soren.brinkm...@xilinx.com> > >> > > > >On the Florida boards there are i2c controlled clocks, power supplies and > >reset signals. Replacing the Cadence I2C controller with a GPIO-bitbang > >controller solved the I2C problems but caused a storm of dozens of deferred > >probes because of the pinmux driver arriving even after the first probe > >attempt of the i2c bus driver. Moving the pinmux driver to an earlier stage > >solved that problem neatly, now the "zynq-pinctrl 700.pinctrl: zynq pinctrl > >initialized" message appears after the OCM driver. > >Judging from your comment the GPIO driver still probes earlier (I don't have > >any GPIO-only pinmuxes yet), so maybe we should amend the patch to probe even > >earlier. The pinmux driver doesn't depend on anything, so it can potentially > >probe very early. What do you think? > > Minor addition: > The gpio-zynq driver probes at "postcore_initcall", so to beat that, the > zynq-pinmux driver should move to "core_initcall" (instead of > "arch_initcall"). That would make the gpio deferral go away. > > An alternative would be to move the gpio driver to "arch", then "postcore" > would be enough for the pinmux. If the gpio probe gets deferred, it > apparently has already been moved to below "subsys" already, with aparently > no ill effects.
Makes me wonder whether a single deferred probe is worth the risk of breaking something by moving these things around. But probably worth a try. Sören -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/