Dear Mika, On Wed, 20 May 2015 15:15:06 +0300 Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > On Wed, May 20, 2015 at 07:34:22PM +0800, Jisheng Zhang wrote: > > Sorry for confusion. Considering one platform which doesn't support power off > > the i2c host but it can disable the host's clock. So in such platform, when > > the host is runtime suspended, its clock is disabled, then i2c_dw_disable() will > > hang when s2ram. > > Right. This happens also when the platform powers off the device. > > > Except using the runtime pm API to ensure the host is in > > a correct state, is there any other solution? AFAIK, 'dev->power.direct_complete' > > doesn't help such case. > > What I had in mind is something like below: > > static int i2c_dw_prepare(struct device *dev) > { > return pm_runtime_suspended(dev); > } > > static void i2c_dw_complete(struct device *dev) > { > if (dev->power.direct_complete) > pm_request_resume(dev); > } > > In other words it checks if the device is already runtime suspended and > prevents ->suspend() etc. from being called. What amazing! I wrote the same code as yours after sending out the last email. > > If that does not work (I didn't try as this problem does not exist on It works! How to submit the patch? Do you mind if I cook the patch and add you signed-off? Thanks a lot, Jisheng -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html