Re: [PATCH 1/2] HID: i2c-hid: The interrupt should be level sensitive

Benjamin Tissoires
2015-01-29T20:10:15Z

On Jan 26 2015 or thereabouts, Mika Westerberg wrote:
> The Microsoft HID over I2C specification says two things regarding the
> interrupt:
>
> 1) The interrupt should be level sensitive
> 2) The device keeps the interrupt asserted as long as it has more reports
> available.
>
> We've seen that at least some Atmel and N-Trig panels keep the line low as
> long as they have something to send. The current version of the driver only
> detects the first edge but then fails to read rest of the reports (as the
> line is still asserted).
>
> Make the driver follow the specification and configure the HID interrupt to
> be level sensitive.
>
> The Windows HID over I2C driver also seems to do the same.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---

FWIW, this one is
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

looks like we are going to drop 2/2, but this one is still valid.

Cheers,
Benjamin

> drivers/hid/i2c-hid/i2c-hid.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index d43e967e7533..8f1dfc5c5d9c 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -785,7 +785,7 @@ static int i2c_hid_init_irq(struct i2c_client *client)
> dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
>
> ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
> - IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> client->name, ihid);
> if (ret < 0) {
> dev_warn(&client->dev,
> --
> 2.1.4
>