[PATCH v3 3/3] HID: i2c-hid: Align i2c_hid_set_power() retry with HID descriptor read

Kenny Levinsen
2024-04-26T22:57:58Z

The retry for HID descriptor and for power commands deals with the same
device quirk, so align the two.

Tested-by: Lukasz Majczak <lma@chromium.org>
Reviewed-by: Lukasz Majczak <lma@chromium.org>
Signed-off-by: Kenny Levinsen <kl@kl.wtf>
---
drivers/hid/i2c-hid/i2c-hid-core.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 6ac1b11fb675..4ec12c083714 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -385,25 +385,21 @@ static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
i2c_hid_dbg(ihid, "%s\n", __func__);

/*
- * Some devices require to send a command to wakeup before power on.
- * The call will get a return value (EREMOTEIO) but device will be
- * triggered and activated. After that, it goes like a normal device.
+ * Some STM-based devices need 400µs after a rising clock edge to wake
+ * from deep sleep, which in turn means that our first command will
+ * fail on a bus error. Certain Weida Tech devices also need this
+ * wake-up. Retry the command in this case.
*/
- if (power_state == I2C_HID_PWR_ON) {
+ ret = i2c_hid_set_power_command(ihid, power_state);
+ if (ret && power_state == I2C_HID_PWR_ON) {
+ usleep_range(400, 500);
ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
-
- /* Device was already activated */
- if (!ret)
- goto set_pwr_exit;
}

- ret = i2c_hid_set_power_command(ihid, power_state);
if (ret)
dev_err(&ihid->client->dev,
"failed to change power setting.\n");

-set_pwr_exit:
-
/*
* The HID over I2C specification states that if a DEVICE needs time
* after the PWR_ON request, it should utilise CLOCK stretching.
--
2.44.0