On Mon, Apr 15, 2024 at 7:14 PM Kenny Levinsen <kl@xxxxxx> wrote: > > On 4/15/24 3:22 PM, Johan Hovold wrote: > > We also use it for devices that may not be populated (e.g. an optional > > touchscreen) and in that case we should not print anything. > > I sent a patch series[0] that shows how the same can be achieved > (gracefully handling missing device + retry to wake device) without any > smbus probes, following the existing retry style in i2c_hid_set_power(). > > Radoslaw and Lukasz, it somehow felt rude to tag and blame you for code > you hadn't seen yet. If my patch ends up favored we should make sure to > have the appropriate attribution tags added... > > [0]: https://lore.kernel.org/all/20240415170517.18780-1-kl@xxxxxx/ > Hi Kenny, Unfortunately, your fix doesn't help in our case as there is no sleep before the second call to i2c_hid_fetch_hid_descriptor(). Saying more, this STM exposes two i2c addresses (connected physically to the same bus) one is the HID interface and the other one gives an access to the base firmware and is served by cros_ec_i2c driver and actually thanks to this driver, touchpad is woken up because In the resume path cros_ec_i2c "starts talking" through the i2c bus thus generating a wakeup interrupt. So we need to send a dummy (or any other) transaction that may fail to wake up the controller after a whole chromebook rebook and on the resume path. Best regards, Lukasz
