From: Ben Gardner <gardner.ben@gmail.com>
To: Jarkko Nikula <jarkko.nikula@linux.intel.com>, linux-i2c@vger.kernel.org
Cc: Ben Gardner <gardner.ben@gmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH] i2c: designware: Fix failure on baytrail
Date: Thu, 8 Feb 2018 12:12:49 -0600 [thread overview]
Message-ID: <1518113569-19991-1-git-send-email-gardner.ben@gmail.com> (raw)
The I2C driver for my Atom E3845 board has been broken since 4.9.
These kernel logs show up whenever am I2C transaction is attempted.
i2c-designware-pci 0000:00:18.3: timeout in disabling adapter
i2c-designware-pci 0000:00:18.3: timeout waiting for bus ready
The root issue is that the I2C port takes a while to enable and somewhere
along the way, the 'enable-and-wait' approach to enabling the adapter
was changed to 'enable'.
That caused the driver and hardware to get out of sync and fail.
I have tested this patch on 4.14 and 4.15.
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
---
drivers/i2c/busses/i2c-designware-master.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index ae69188..55926ef 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -209,7 +209,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
i2c_dw_disable_int(dev);
/* Enable the adapter */
- __i2c_dw_enable(dev, true);
+ __i2c_dw_enable_and_wait(dev, true);
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
--
2.7.4
next reply other threads:[~2018-02-08 18:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-08 18:12 Ben Gardner [this message]
2018-02-09 9:25 ` [PATCH] i2c: designware: Fix failure on baytrail Jarkko Nikula
2018-02-09 15:07 ` Ben Gardner
2018-02-13 14:35 ` Jarkko Nikula
2018-02-13 16:31 ` Ben Gardner
2018-02-14 15:06 ` Jarkko Nikula
-- strict thread matches above, loose matches on Subject: below --
2018-02-12 15:52 Ben Gardner
2018-02-12 15:56 ` Ben Gardner
2018-02-13 14:36 ` Jarkko Nikula
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