HID: i2c-hid: Skip ELAN power-on command after reset

commit ca66a6770bd9d6d99e469debd1c7363ac455daf9 upstream.

For ELAN touchscreen, we found our boot code of IC was not flexible enough
to receive and handle this command.
Once the FW main code of our controller is crashed for some reason,
the controller could not be enumerated successfully to be recognized
by the system host. therefore, it lost touch functionality.

Add quirk for skip send power-on command after reset.
It will impact to ELAN touchscreen and touchpad on HID over I2C projects.

Fixes: 43b7029f475e ("HID: i2c-hid: Send power-on command after reset").
Cc: stable@vger.kernel.org
Signed-off-by: Johnny Chuang <johnny.chuang.emc@gmail.com>
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index f67817819f9aa6ce7a446c32c3ccac999236e202..6f7a3702b5fba7ff2e53db5bb169905b77c072c0 100644 (file)
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -50,6 +50,7 @@
 #define I2C_HID_QUIRK_BOGUS_IRQ                        BIT(4)
 #define I2C_HID_QUIRK_RESET_ON_RESUME          BIT(5)
 #define I2C_HID_QUIRK_BAD_INPUT_SIZE           BIT(6)
+#define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET    BIT(7)
 
 
 /* flags */
@@ -185,6 +186,11 @@ static const struct i2c_hid_quirks {
                 I2C_HID_QUIRK_RESET_ON_RESUME },
        { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
                I2C_HID_QUIRK_BAD_INPUT_SIZE },
+       /*
+        * Sending the wakeup after reset actually break ELAN touchscreen controller
+        */
+       { USB_VENDOR_ID_ELAN, HID_ANY_ID,
+                I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET },
        { 0, 0 }
 };
 
@@ -468,7 +474,8 @@ static int i2c_hid_hwreset(struct i2c_client *client)
        }
 
        /* At least some SIS devices need this after reset */
-       ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
+       if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
+               ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
 
 out_unlock:
        mutex_unlock(&ihid->reset_lock);