[PATCH v5 1/8] mfd: cros_ec: fail early if we cannot identify the EC

From: Enric Balletbo i Serra
Date: Thu Apr 05 2018 - 07:33:27 EST

From: Vincent Palatin <vpalatin@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
Acked-by: Benson Leung <bleung@xxxxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Reviewed-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

drivers/mfd/cros_ec.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index d61024141e2b..74780f2964a1 100644
--- 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)


- 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,