* Dave Gerlach <d-gerlach@xxxxxx> [150305 11:53]: > On 03/05/2015 12:49 PM, Tony Lindgren wrote: > > * Paul Walmsley <paul@xxxxxxxxx> [150305 10:16]: > >> On Thu, 5 Mar 2015, Dave Gerlach wrote: > >> > >>> Introduce a dt property, ti,no-init, that prevents hwmod initialization. > >>> Even if a dt node is marked as disabled, hwmod still at least enables > >>> the hwmod and programs the sysconfig before attempting to idle it at > >>> boot. If an IP has been disabled by the hardware configuration on a > >>> platform, this will cause a hang due to writing to inactive registers. > >>> This property prevents that from happening by marking the hwmod as > >>> _HWMOD_STATE_DISABLED during init. > >> > >> I'm kind of wondering if hwmod should even touch a device if it's marked > >> as disabled in the DT. Tony, what do you think? > > > > Well nothing happens if a device is status = "disabled". No dev entry > > gets created for it at all and hwmod won't have any data for the device > > populated. The only way hwmod code could see that device if the device > > gets it's data from the legacy omap_hwmod_*_data.c instead of DT. > > > > We still need this for the sysconfig programming, correct? hwmod programs that > regardless of dt status and then idles the IP, Well hwmod does not even know about the IP IO addresses if it's marked with status = "disabled".. Which IP are you having problems with? > which is why I needed the ti,no-init for the epos evm. It isn't just a > matter of we shouldnt write to it because we don't want to use it; we > can't write to it because the module is held off so it causes an > external abort if we do. Well hard to say not knowing which module this is.. Pretty much all the modules have drivers and the driver just does pm_runtime_get() on it? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
