Messages in this thread | | | Date | Mon, 17 Nov 2014 12:57:44 +0100 | From | Thierry Reding <> | Subject | Re: [PATCH 5/8] thermal:cpu cooling:tegra: Provide deferred probing for tegra driver |
| |
On Fri, Nov 14, 2014 at 12:24:37PM +0100, Lukasz Majewski wrote: > Hi Mikko, > > > Tested-by: Mikko Perttunen <mikko.perttunen@kapsi.fi> > > Thanks for testing. > > > > > One potential issue I can see is that if the cpufreq driver fails to > > probe then you'll never get the thermal driver either. For example, > > Tegra124 currently has no cpufreq driver, so if CONFIG_CPU_THERMAL > > was enabled, then the soctherm driver would never be able to probe. > > Yes, this is a potential issue. However, this option in tegra_defconfig > is by default disabled when thermal is enabled.
Not everybody uses tegra_defconfig for their kernel builds. In fact I'd imagine that the majority of kernels use a variant of multi_v7_defconfig and therefore CPU_THERMAL might get enabled irrespective of any Tegra support.
I think a better solution would be to add this check only when proper support for CPU frequency based cooling is added. That is, when a call to cpufreq_cooling_register() (or a variant thereof) is added.
But while at it, why not make it so that cpufreq_cooling_register() detects if a cpufreq driver has been registered yet and propagate -EPROBE_DEFER if necessary?
Thierry [unhandled content-type:application/pgp-signature] | |