Re: [ibm-acpi-devel] [PATCH v2] Input: document inhibiting
On Wed, Jun 17, 2020 at 12:18:22PM +0200, Andrzej Pietrasiewicz wrote: > Document inhibiting input devices and its relation to being > a wakeup source. > > Signed-off-by: Andrzej Pietrasiewicz Applied, thank you. -- Dmitry ___ ibm-acpi-devel mailing list ibm-acpi-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
Re: [ibm-acpi-devel] [PATCH v2] Input: document inhibiting
Hi! > +Inhibiting input devices > + > + > +Inhibiting a device means ignoring input events from it. As such it is about > maintaining > +relationships with input handlers - either already existing relationships, > or relationships > +to be established while the device is in inhibited state. > + > +If a device is inhibited, no input handler will receive events from it. > + > +The fact that nobody wants events from the device is exploited further, by > calling device's > +close() (if there are users) and open() (if there are users) on inhibit and > uninhibit > +operations, respectively. Indeed, the meaning of close() is to stop > providing events > +to the input core and that of open() is to start providing events to the > input core. > + > +Calling the device's close() method on inhibit (if there are users) allows > the driver > +to save power. Either by directly powering down the device or by releasing > the > +runtime-pm reference it got in open() when the driver is using runtime-pm. > + > +Inhibiting and uninhibiting are orthogonal to opening and closing the device > by input > +handlers. Userspace might want to inhibit a device in anticipation before > any handler is > +positively matched against it. Ok. > +Inhibiting and uninhibiting are orthogonal to device's being a wakeup > source, too. > Being a +wakeup source plays a role when the system is sleeping, not when the > system is > operating. +How drivers should program their interaction between inhibiting, > sleeping > and being a wakeup +source is driver-specific. + +Taking the analogy with the > network I don't believe making interaction driver-specific is good idea. We should decide what reasonable behaviour is and then make drivers implement that... Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html ___ ibm-acpi-devel mailing list ibm-acpi-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
Re: [ibm-acpi-devel] [PATCH v2] Input: document inhibiting
On 6/17/20 3:18 AM, Andrzej Pietrasiewicz wrote: > Document inhibiting input devices and its relation to being > a wakeup source. > > Signed-off-by: Andrzej Pietrasiewicz > --- > v1..v2: > > - Addressed editorial comments from Randy > - Added a paragraph by Hans > > Documentation/input/input-programming.rst | 40 +++ > 1 file changed, 40 insertions(+) > > diff --git a/Documentation/input/input-programming.rst > b/Documentation/input/input-programming.rst > index 45a4c6e05e39..7432315cc829 100644 > --- a/Documentation/input/input-programming.rst > +++ b/Documentation/input/input-programming.rst > @@ -164,6 +164,46 @@ disconnects. Calls to both callbacks are serialized. > The open() callback should return a 0 in case of success or any nonzero value > in case of failure. The close() callback (which is void) must always succeed. > > +Inhibiting input devices > + > + > +Inhibiting a device means ignoring input events from it. As such it is about > maintaining > +relationships with input handlers - either already existing relationships, > or relationships > +to be established while the device is in inhibited state. > + > +If a device is inhibited, no input handler will receive events from it. > + > +The fact that nobody wants events from the device is exploited further, by > calling device's > +close() (if there are users) and open() (if there are users) on inhibit and > uninhibit > +operations, respectively. Indeed, the meaning of close() is to stop > providing events > +to the input core and that of open() is to start providing events to the > input core. > + > +Calling the device's close() method on inhibit (if there are users) allows > the driver > +to save power. Either by directly powering down the device or by releasing > the > +runtime-pm reference it got in open() when the driver is using runtime-pm. > + > +Inhibiting and uninhibiting are orthogonal to opening and closing the device > by input > +handlers. Userspace might want to inhibit a device in anticipation before > any handler is > +positively matched against it. > + > +Inhibiting and uninhibiting are orthogonal to device's being a wakeup > source, too. Being a > +wakeup source plays a role when the system is sleeping, not when the system > is operating. > +How drivers should program their interaction between inhibiting, sleeping > and being a wakeup > +source is driver-specific. > + > +Taking the analogy with the network devices - bringing a network interface > down doesn't mean > +that it should be impossible be wake the system up on LAN through this > interface. So, there > +may be input drivers which should be considered wakeup sources even when > inhibited. Actually, > +in many I2C input devices their interrupt is declared a wakeup interrupt and > its handling > +happens in driver's core, which is not aware of input-specific inhibit (nor > should it be). > +Composite devices containing several interfaces can be inhibited on a > per-interface basis and > +e.g. inhibiting one interface shouldn't affect the device's capability of > being a wakeup source. > + > +If a device is to be considered a wakeup source while inhibited, special > care must be taken when > +programming its suspend(), as it might need to call device's open(). > Depending on what close() > +means for the device in question, not opening() it before going to sleep > might make it > +impossible to provide any wakeup events. The device is going to sleep anyway. > + > Basic event types > ~ > > Reviewed-by: Randy Dunlap Thanks. -- ~Randy ___ ibm-acpi-devel mailing list ibm-acpi-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
Re: [ibm-acpi-devel] [PATCH v2] Input: document inhibiting
Hi, On 6/17/20 12:18 PM, Andrzej Pietrasiewicz wrote: Document inhibiting input devices and its relation to being a wakeup source. Signed-off-by: Andrzej Pietrasiewicz --- v1..v2: - Addressed editorial comments from Randy - Added a paragraph by Hans Thank you. v2 looks good to me: Reviewed-by: Hans de Goede Regards, Hans Documentation/input/input-programming.rst | 40 +++ 1 file changed, 40 insertions(+) diff --git a/Documentation/input/input-programming.rst b/Documentation/input/input-programming.rst index 45a4c6e05e39..7432315cc829 100644 --- a/Documentation/input/input-programming.rst +++ b/Documentation/input/input-programming.rst @@ -164,6 +164,46 @@ disconnects. Calls to both callbacks are serialized. The open() callback should return a 0 in case of success or any nonzero value in case of failure. The close() callback (which is void) must always succeed. +Inhibiting input devices + + +Inhibiting a device means ignoring input events from it. As such it is about maintaining +relationships with input handlers - either already existing relationships, or relationships +to be established while the device is in inhibited state. + +If a device is inhibited, no input handler will receive events from it. + +The fact that nobody wants events from the device is exploited further, by calling device's +close() (if there are users) and open() (if there are users) on inhibit and uninhibit +operations, respectively. Indeed, the meaning of close() is to stop providing events +to the input core and that of open() is to start providing events to the input core. + +Calling the device's close() method on inhibit (if there are users) allows the driver +to save power. Either by directly powering down the device or by releasing the +runtime-pm reference it got in open() when the driver is using runtime-pm. + +Inhibiting and uninhibiting are orthogonal to opening and closing the device by input +handlers. Userspace might want to inhibit a device in anticipation before any handler is +positively matched against it. + +Inhibiting and uninhibiting are orthogonal to device's being a wakeup source, too. Being a +wakeup source plays a role when the system is sleeping, not when the system is operating. +How drivers should program their interaction between inhibiting, sleeping and being a wakeup +source is driver-specific. + +Taking the analogy with the network devices - bringing a network interface down doesn't mean +that it should be impossible be wake the system up on LAN through this interface. So, there +may be input drivers which should be considered wakeup sources even when inhibited. Actually, +in many I2C input devices their interrupt is declared a wakeup interrupt and its handling +happens in driver's core, which is not aware of input-specific inhibit (nor should it be). +Composite devices containing several interfaces can be inhibited on a per-interface basis and +e.g. inhibiting one interface shouldn't affect the device's capability of being a wakeup source. + +If a device is to be considered a wakeup source while inhibited, special care must be taken when +programming its suspend(), as it might need to call device's open(). Depending on what close() +means for the device in question, not opening() it before going to sleep might make it +impossible to provide any wakeup events. The device is going to sleep anyway. + Basic event types ~ ___ ibm-acpi-devel mailing list ibm-acpi-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
