mfd: cros_ec: Fail early if we cannot identify the EC

[ Upstream commit 0dbbf25561b29ffab5ba6277429760abdf49ceff ]

If we cannot communicate with the EC chip to detect the protocol version
and its features, it's very likely useless to continue. Else we will
commit all kind of uninformed mistakes (using the wrong protocol, the
wrong buffer size, mixing the EC with other chips).

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Acked-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index b0ca5a4c841e0c98828efbcebf42caca3223006b..c5528ae982f26ab90721fa33525d60cf5df731a9 100644 (file)
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -112,7 +112,11 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 
        mutex_init(&ec_dev->lock);
 
-       cros_ec_query_all(ec_dev);
+       err = cros_ec_query_all(ec_dev);
+       if (err) {
+               dev_err(dev, "Cannot identify the EC: error %d\n", err);
+               return err;
+       }
 
        if (ec_dev->irq) {
                err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,