[PATCH] mfd: cros-ec: copy the whole event when msg->version is 0

From: Emil Karlson <jekarlson@gmail.com>
To: Emil Renner Berthing <kernel@esmil.dk>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Stefan Adolfsson <sadolfsson@chromium.org>,
	linux-kernel@vger.kernel.org
Cc: Emil Karlson <jekarlson@gmail.com>
Subject: [PATCH] mfd: cros-ec: copy the whole event when msg->version is 0
Date: Thu, 27 Sep 2018 12:24:27 +0300	[thread overview]
Message-ID: <20180927092427.507-1-jekarlson@gmail.com> (raw)

Commit 57e94c8b974db2d83c60e1139c89a70806abbea0 caused cros-ec keyboard events
be truncated on many chromebooks so that Left and Right keys on Column 12 were
always 0. This commit fixes the issue by restoring the old semantics when the
protocol version is 0.
---
 drivers/platform/chrome/cros_ec_proto.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 398393ab5df8..457e4940dba4 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -519,8 +519,14 @@ static int get_next_event_xfer(struct cros_ec_device *ec_dev,
 
 	ret = cros_ec_cmd_xfer(ec_dev, msg);
 	if (ret > 0) {
+		unsigned int copy_size;
+
 		ec_dev->event_size = ret - 1;
-		memcpy(&ec_dev->event_data, msg->data, ec_dev->event_size);
+		if (!version)
+			copy_size = sizeof(struct ec_response_get_next_event);
+		else
+			copy_size = ec_dev->event_size;
+		memcpy(&ec_dev->event_data, msg->data, copy_size);
 	}
 
 	return ret;
-- 
2.19.0

