Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Brian Norris <briannorris@chromium.org>
To:     Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>
Cc:     chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org,
        Brian Norris <briannorris@chromium.org>
Subject: [PATCH 4/5] platform/chrome: cros_ec_lightbar: Set PROBE_PREFER_ASYNCHRONOUS
Date:   Fri, 28 Oct 2022 14:14:48 -0700
Message-Id: <20221028141411.4.I565598102e0bfb03bdf8c090d3bfdf954d026bc5@changeid>
In-Reply-To: <20221028141411.1.I0728421299079b104710c202d5d7095b2674fd8c@changeid>
References: <20221028141411.1.I0728421299079b104710c202d5d7095b2674fd8c@changeid>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This driver takes on the order of 15ms to start on some systems. Even on
systems where there is no lightbar support, it can take a few
milliseconds just to probe the EC for support. It shouldn't have many
cross-device dependencies to race with, nor racy access to shared state
with other drivers, so this should be a relatively low risk change.

This driver was pinpointed as part of a survey of top slowest initcalls
(i.e., are built in, and probing synchronously) on a lab of ChromeOS
systems.

Signed-off-by: Brian Norris <briannorris@chromium.org>
---

 drivers/platform/chrome/cros_ec_lightbar.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index 469dfc7a4a03..ff4d619cf924 100644
--- a/drivers/platform/chrome/cros_ec_lightbar.c
+++ b/drivers/platform/chrome/cros_ec_lightbar.c
@@ -601,6 +601,7 @@ static struct platform_driver cros_ec_lightbar_driver = {
 	.driver = {
 		.name = DRV_NAME,
 		.pm = &cros_ec_lightbar_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe = cros_ec_lightbar_probe,
 	.remove = cros_ec_lightbar_remove,
-- 
2.38.1.273.g43a17bfeac-goog