On Mon, Mar 13, 2017 at 12:01:59PM +0100, Benjamin Tissoires wrote: > On Mar 10 2017 or thereabouts, Dmitry Torokhov wrote: > > From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > > > > This provides glue between PS/2 devices that enumerate the RMI4 devices > > and Elan touchpads to the RMI4 (or Elan) SMBus driver. > > > > The SMBus devices keep their PS/2 connection alive. If the initialization > > process goes too far (psmouse_activate called), the device disconnects > > from the I2C bus and stays on the PS/2 bus, that is why we explicitly > > disable PS/2 device reporting (by calling psmouse_deactivate) before > > trying to register SMBus companion device. > > > > The HID over I2C devices are enumerated through the ACPI DSDT, and > > their PS/2 device also exports the InterTouch bit in the extended > > capability 0x0C. However, the firmware keeps its I2C connection open > > even after going further in the PS/2 initialization. We don't need > > to take extra precautions with those device, especially because they > > block their PS/2 communication when HID over I2C is used. > > > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > > --- > > Actually, one thing I noticed but forgot to say in my previous email: > > If you call rescan from the sysfs, there is a chance the i2c device is > still there while we are trying to reconnect the device. Which means > that we fail at creating the i2c device, and then fall back on PS/2. > > It's not a big issue, but still it will show some warning in the dmesg > while attempting to create some sysfs files that already exist. > > S solution could be to unlock the mutexes and wait for the termination > of i2c_unregister_device, but I would believe the best approach would be > to remove the mutexes in serio and psmouse, and directly call > i2c_unregister_device in .disconnect. Yeah, I think we'll have to live with rescan from sysfs hiccuping for now. I want to do a bit of face-lift for serio/psmouse, but it will take a bit of time. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
