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From:   Marius Zachmann <mail@mariuszachmann.de>
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Marius Zachmann <mail@mariuszachmann.de>,
        Jean Delvare <jdelvare@suse.com>, linux-hwmon@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] hwmon: corsair-cpro: fix ccp_probe, add delay
Date:   Mon, 17 Aug 2020 08:54:28 +0200
Message-Id: <20200817065428.5974-1-mail@mariuszachmann.de>
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Possibly because of the changes in usbhid/hid-core.c the first
raw input report is not received during ccp_probe function and it will timeout.
I am not sure, whether this behaviour is expected after hid_device_io_start or if I
am missing something.
As a solution this adds msleep(50) to ccp_probe so that all initial input reports can
be received.

Signed-off-by: Marius Zachmann <mail@mariuszachmann.de>
---
 drivers/hwmon/corsair-cpro.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/corsair-cpro.c b/drivers/hwmon/corsair-cpro.c
index 591929ec217a..6359409e6c71 100644
--- a/drivers/hwmon/corsair-cpro.c
+++ b/drivers/hwmon/corsair-cpro.c
@@ -10,6 +10,7 @@

 #include <linux/bitops.h>
 #include <linux/completion.h>
+#include <linux/delay.h>
 #include <linux/hid.h>
 #include <linux/hwmon.h>
 #include <linux/kernel.h>
@@ -513,8 +514,8 @@ static int ccp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	init_completion(&ccp->wait_input_report);

 	hid_device_io_start(hdev);
+	msleep(50); /* make sure, events can be received */

-	/* temp and fan connection status only updates when device is powered on */
 	ret = get_temp_cnct(ccp);
 	if (ret)
 		goto out_hw_close;
--
2.28.0