On Fri, Dec 18, 2015 at 7:38 AM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> On Fri, Dec 18, 2015 at 04:42:09PM +0200, Mika Westerberg wrote:
>> On another occasion the faulty input report was received immediatelly
>> after we call i2c_hid_set_power().
>>
>> With below hack patch suspend/resume works fine but it is far from being
>> suitable for merging. Still, it would be nice if you could try it out
>> and see if it helps in your case.
>
> Actually it looks like we can handle this by just ignoring input reports
> while we are resetting the device. Following seems to work as well.
FWIW,
Tested-by: Nishanth Aravamudan <nish.aravamudan@xxxxxxxxx>
and if you can Cc me on any follow-up/alternative patches, I will be
happy to test those too!
Thanks!
-Nish
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index 10bd8e6..eeaf33a 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -352,13 +352,24 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
> static int i2c_hid_hwreset(struct i2c_client *client)
> {
> struct i2c_hid *ihid = i2c_get_clientdata(client);
> + bool started;
> int ret;
>
> i2c_hid_dbg(ihid, "%s\n", __func__);
>
> + /*
> + * Some touchpads seem to send input reports once their power is
> + * turned back on after resume. This confuses our reset logic
> + * below.
> + *
> + * Prevent handling any input reports while we are resetting the
> + * device.
> + */
> + started = test_and_clear_bit(I2C_HID_STARTED, &ihid->flags);
> +
> ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
> if (ret)
> - return ret;
> + goto out;
>
> i2c_hid_dbg(ihid, "resetting...\n");
>
> @@ -366,10 +377,14 @@ static int i2c_hid_hwreset(struct i2c_client *client)
> if (ret) {
> dev_err(&client->dev, "failed to reset device.\n");
> i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> - return ret;
> + goto out;
> }
>
> - return 0;
> +out:
> + if (started)
> + set_bit(I2C_HID_STARTED, &ihid->flags);
> +
> + return ret;
> }
>
> static void i2c_hid_get_input(struct i2c_hid *ihid)
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