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From:   Dmitry Osipenko <digetx@gmail.com>
To:     Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Laxman Dewangan <ldewangan@nvidia.com>,
        Wolfram Sang <wsa@the-dreams.de>
Cc:     linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v1] i2c: tegra: Make timeout error more informative
Date:   Mon,  2 Mar 2020 20:35:12 +0300
Message-Id: <20200302173512.2743-1-digetx@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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The I2C timeout error message doesn't tell us what exactly failed and some
I2C client drivers do not clarify the error either. Adding WARN_ON_ONCE()
results in a stacktrace being dumped into KMSG, which is very useful for
debugging purposes.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/i2c/busses/i2c-tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index cbc2ad49043e..b2bb19e05248 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -1245,7 +1245,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 	tegra_i2c_mask_irq(i2c_dev, int_mask);
 
-	if (time_left == 0) {
+	if (WARN_ON_ONCE(time_left == 0)) {
 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
 		tegra_i2c_init(i2c_dev, true);
 		return -ETIMEDOUT;
-- 
2.25.1