openwrtv4/target/linux/brcm2708/patches-4.9/950-0108-i2c-bcm2835-Use-dev_dbg-logging-on-transfer-errors.patch
Rafał Miłecki fce21ae4cc brcm2708: rename all patches from raspberrypi git tree to use 950 prefix
Right now all brcm2708 patches are extracted from the non-mainline
raspberrypi/linux git tree. Many of them are hacks and/or are unneeded
in LEDE. Raspberry Pi is getting better and better mainline support so
it would be nice to finally start maintaining patches in a cleaner way:
1) Backport patches accepted in upstream tree
2) Start using upstream drivers
3) Pick only these patches that are needed for more complete support

Handling above tasks requires grouping patches - ideally using the same
prefixes as generic ones. It means we should rename existing patches to
use some high prefix. This will allow e.g. use 0xx for backported code.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Stijn Tintel <stijn@linux-ipv6.be>
2017-03-24 08:06:35 +01:00

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From bff25210b88dc7b71ee9c2626e42a939072dec64 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
Date: Mon, 19 Sep 2016 17:19:41 +0200
Subject: [PATCH] i2c: bcm2835: Use dev_dbg logging on transfer errors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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>
Reviewed-by: Eric Anholt <eric@anholt.net>
---
drivers/i2c/busses/i2c-bcm2835.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -216,7 +216,7 @@ static int bcm2835_i2c_xfer_msg(struct b
(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;