On Thu, Sep 12, 2013 at 2:34 PM, Kevin Hilman <khilman@xxxxxxxxxx> wrote: > Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> writes: > >> From: Aaron Lu <aaron.lu@xxxxxxxxx> >> >> This patch adds runtime PM support for the I2C bus in a similar way that >> has been done for PCI bus already. This means that the I2C bus core >> prepares runtime PM for a client device just before a driver is about to be >> bound to it. Devices that are not bound to any driver are not prepared for >> runtime PM. >> >> In order to take advantage of this runtime PM support, the client device >> driver needs drop the device runtime PM reference count by calling >> pm_runtime_put() in its ->probe() callback and possibly implement rest of >> the runtime PM callbacks. >> >> If the driver doesn't support runtime PM (like most of the existing I2C >> client drivers), the device in question is regarded as being runtime PM >> active and powered on. > > But for existing drivers which already support runtime PM (at least 7 by > a quick grep), they will be stuck runtime enabled and stop hitting > low-power states after this patch. Oops, nevermind. I was mixing this up with runtime PM on the i2c adapter but this is for the i2c client. Sorry for the noise. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
