On Wed, 20 May 2015 20:34:30 +0800 Jisheng Zhang <[email protected]> wrote:
> Dear Mika, > > On Wed, 20 May 2015 15:15:06 +0300 > Mika Westerberg <[email protected]> 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? > PS: If you cook the patch instead, feel free to add my acked-by and tested-by Thanks a lot for the direct_complete idea, Jisheng -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
