On Jul 11 2014 or thereabouts, Andrew Duggan wrote: > Currently, the i2c-hid driver does not call the suspend, resume, and > reset_resume callbacks in the hid_driver struct when those events occur. > This means that HID drivers for i2c-hid devices will not be able to execute > commands which may be needed during suspend or resume. One example is when a > touchpad using the hid-multitouch driver gets reset by i2c-hid coming out of > resume. Since the reset_resume callback never gets called the device is never > put back into the correct input mode. This patch calls the suspend and resume > callbacks and tries to duplicate the functionality of the usb-hid driver. > > Signed-off-by: Andrew Duggan <[email protected]> > Signed-off-by: Vincent Huang <[email protected]> > --- > Hi Benjamin, > > This is the patch which Vincent and I came up with to fix the behavior which > we were seeing with touchpads not being operational after resuming. We only > use the reset_resume callback since i2c_hid_resume is always doing a hardware > reset and it doesn't seem like there is a condition in which the standard > resume callback would be appropriate. Also, is a full hardware reset always > needed when resuming?
Hi Andrew, well, the PM management of i2c_hid has been handled by Mika (in CC) and I am unfortunately not able to have a strong opinion on this. I still lack of hardware properly supporting the suspend/resume mechanism. So, you are in charge of that. IIRC, nothing prevents from not calling hw_reset, but I guess this was the safer implementation we could have. Anyway, the patch looks good: Reviewed-by: Benjamin Tissoires <[email protected]> Cheers, Benjamin > > drivers/hid/i2c-hid/i2c-hid.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c > index 21aafc8..747d544 100644 > --- a/drivers/hid/i2c-hid/i2c-hid.c > +++ b/drivers/hid/i2c-hid/i2c-hid.c > @@ -1054,21 +1054,29 @@ static int i2c_hid_remove(struct i2c_client *client) > static int i2c_hid_suspend(struct device *dev) > { > struct i2c_client *client = to_i2c_client(dev); > + struct i2c_hid *ihid = i2c_get_clientdata(client); > + struct hid_device *hid = ihid->hid; > + int ret = 0; > > disable_irq(client->irq); > if (device_may_wakeup(&client->dev)) > enable_irq_wake(client->irq); > > + if (hid->driver && hid->driver->suspend) > + ret = hid->driver->suspend(hid, PMSG_SUSPEND); > + > /* Save some power */ > i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); > > - return 0; > + return ret; > } > > static int i2c_hid_resume(struct device *dev) > { > int ret; > struct i2c_client *client = to_i2c_client(dev); > + struct i2c_hid *ihid = i2c_get_clientdata(client); > + struct hid_device *hid = ihid->hid; > > enable_irq(client->irq); > ret = i2c_hid_hwreset(client); > @@ -1078,6 +1086,11 @@ static int i2c_hid_resume(struct device *dev) > if (device_may_wakeup(&client->dev)) > disable_irq_wake(client->irq); > > + if (hid->driver && hid->driver->reset_resume) { > + ret = hid->driver->reset_resume(hid); > + return ret; > + } > + > return 0; > } > #endif > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
