[PATCH] hid: i2c: let RMI devices decide what constitutes wakeup event

[PATCH] hid: i2c: let RMI devices decide what constitutes wakeup event

[Dmitry Torokhov]

HID-RMI is special in the sense that it does not carry HID events
directly, but rather uses HID protocol as a wrapper/transport for RMI
protocol.  Therefore we should not assume that all data coming from the
device via interrupt is associated with user activity and report wakeup
event indiscriminately, but rather let HID-RMI do that when appropriate.

HID-RMI devices tag responses to the commands issued by the host as
RMI_READ_DATA_REPORT_ID whereas motion and other input events from the
device are tagged as RMI_ATTN_REPORT_ID. Change hid-rmi to report wakeup
events when receiving the latter packets. This allows ChromeOS to
accurately identify wakeup source and make correct decision on the mode
of the resume the system should take ("dark" where the display stays off
vs normal one).

Fixes: d951ae1ce803 ("HID: i2c-hid: Report wakeup events")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-rmi.c              | 2 ++
 drivers/hid/i2c-hid/i2c-hid-core.c | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
index bb1f423f4ace..84e7ba5314d3 100644
--- a/drivers/hid/hid-rmi.c
+++ b/drivers/hid/hid-rmi.c
@@ -326,6 +326,8 @@ static int rmi_input_event(struct hid_device *hdev, u8 *data, int size)
 	if (!(test_bit(RMI_STARTED, &hdata->flags)))
 		return 0;
 
+	pm_wakeup_event(hdev->dev.parent, 0);
+
 	local_irq_save(flags);
 
 	rmi_set_attn_data(rmi_dev, data[1], &data[2], size - 2);
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 0667b6022c3b..a9428b7f34a4 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -554,7 +554,8 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
 	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
 
 	if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
-		pm_wakeup_event(&ihid->client->dev, 0);
+		if (ihid->hid->group != HID_GROUP_RMI)
+			pm_wakeup_event(&ihid->client->dev, 0);
 
 		hid_input_report(ihid->hid, HID_INPUT_REPORT,
 				ihid->inbuf + sizeof(__le16),
-- 
2.38.1.584.g0f3c55d4c2-goog


-- 
Dmitry

Re: [PATCH] hid: i2c: let RMI devices decide what constitutes wakeup event

[Jiri Kosina]

On Fri, 18 Nov 2022, Dmitry Torokhov wrote:

> HID-RMI is special in the sense that it does not carry HID events
> directly, but rather uses HID protocol as a wrapper/transport for RMI
> protocol.  Therefore we should not assume that all data coming from the
> device via interrupt is associated with user activity and report wakeup
> event indiscriminately, but rather let HID-RMI do that when appropriate.
> 
> HID-RMI devices tag responses to the commands issued by the host as
> RMI_READ_DATA_REPORT_ID whereas motion and other input events from the
> device are tagged as RMI_ATTN_REPORT_ID. Change hid-rmi to report wakeup
> events when receiving the latter packets. This allows ChromeOS to
> accurately identify wakeup source and make correct decision on the mode
> of the resume the system should take ("dark" where the display stays off
> vs normal one).
> 
> Fixes: d951ae1ce803 ("HID: i2c-hid: Report wakeup events")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Applied, thanks Dmitry.

-- 
Jiri Kosina
SUSE Labs