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From: "Noralf Trønnes" <noralf@tronnes.org>
To: wsa@the-dreams.de, swarren@wwwdotorg.org, eric@anholt.net
Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-rpi-kernel@lists.infradead.org,
	"Noralf Trønnes" <noralf@tronnes.org>
Subject: [PATCH v3 3/7] i2c: bcm2835: Use dev_dbg logging on transfer errors
Date: Wed, 28 Sep 2016 19:50:52 +0200	[thread overview]
Message-ID: <1475085056-5205-4-git-send-email-noralf@tronnes.org> (raw)
In-Reply-To: <1475085056-5205-1-git-send-email-noralf@tronnes.org>

Writing to an AT24C32 generates on average 2x i2c transfer errors per
32-byte page write. Which amounts to a lot for a 4k write. This is due
to the fact that the chip doesn't respond during it's internal write
cycle when the at24 driver tries and retries the next write.
Only a handful drivers use dev_err() on transfer error, so switch to
dev_dbg() instead.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---

Changes:
- use dev_dbg instead of dev_err_ratelimited

 drivers/i2c/busses/i2c-bcm2835.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index df036ed..8cdb139 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -207,7 +207,7 @@ static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev,
 	    (msg->flags & I2C_M_IGNORE_NAK))
 		return 0;

-	dev_err(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err);
+	dev_dbg(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err);

 	if (i2c_dev->msg_err & BCM2835_I2C_S_ERR)
 		return -EREMOTEIO;
--
2.8.2

  parent reply	other threads:[~2016-09-28 17:52 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-28 17:50 [PATCH v3 0/7] i2c: bcm2835: Bring in changes from downstream Noralf Trønnes
2016-09-28 17:50 ` [PATCH v3 1/7] i2c: bcm2835: Fix hang for writing messages larger than 16 bytes Noralf Trønnes
2016-09-28 17:50 ` [PATCH v3 2/7] i2c: bcm2835: Protect against unexpected TXW/RXR interrupts Noralf Trønnes
2016-09-28 22:00   ` Eric Anholt
2016-09-28 22:22     ` Noralf Trønnes
2016-09-29  5:37       ` Stefan Wahren
2016-10-02 14:19         ` Noralf Trønnes
2016-10-03 18:58           ` Eric Anholt
2016-10-03 19:42       ` Eric Anholt
2016-10-04 19:24         ` Noralf Trønnes
2016-09-28 17:50 ` Noralf Trønnes [this message]
2016-09-29 11:05   ` [PATCH v3 3/7] i2c: bcm2835: Use dev_dbg logging on transfer errors Martin Sperl
2016-09-28 17:50 ` [PATCH v3 4/7] i2c: bcm2835: Can't support I2C_M_IGNORE_NAK Noralf Trønnes
2016-09-28 17:50 ` [PATCH v3 5/7] i2c: bcm2835: Add support for Repeated Start Condition Noralf Trønnes
2016-09-28 17:50 ` [PATCH v3 6/7] i2c: bcm2835: Support i2c-dev ioctl I2C_TIMEOUT Noralf Trønnes
2016-09-28 17:50 ` [PATCH v3 7/7] i2c: bcm2835: Add support for dynamic clock Noralf Trønnes
2016-09-28 21:24   ` Eric Anholt
2016-09-28 22:10     ` Noralf Trønnes
2016-09-29  8:02     ` Martin Sperl

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