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

Message ID 20240426225739.2166-4-kl@kl.wtf (mailing list archive)
State New
Delegated to: Jiri Kosina
Headers show
Series HID: i2c-hid: Probe and wake device with HID descriptor fetch | expand

Commit Message

Kenny Levinsen April 26, 2024, 10:47 p.m. UTC 
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(-)
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Patch

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.