From 43b7029f475e7497da1de1f4a1742241812bf266 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sun, 20 Oct 2019 23:47:18 +0200 Subject: [PATCH] HID: i2c-hid: Send power-on command after reset Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management"), any i2c-hid touchscreens would typically be runtime-suspended between the driver loading and Xorg or a Wayland compositor opening it, causing it to be resumed again. This means that before this change, we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the graphical session would start listening to the touchscreen. It turns out that at least some SIS touchscreens, such as the one found on the Asus T100HA, need a power-on command after reset, otherwise they will not send any events. Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management") Cc: Kai-Heng Feng Signed-off-by: Hans de Goede Signed-off-by: Jiri Kosina --- drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index d9c55e3..04c08813 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -447,8 +447,12 @@ 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); + goto out_unlock; } + /* At least some SIS devices need this after reset */ + ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); + out_unlock: mutex_unlock(&ihid->reset_lock); return ret; -- 2.7.4