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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-06 11:26:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-06 11:26:01 -0800
commit15bd1e5cb36306a015328aa1c2b6470a25153171 (patch)
tree0be8953bd75522e6d0aca7ef332cc23a179b1f04
parentbeb5af4033cbeae2d50b4a6d770ab8901fd34d7a (diff)
parent681d15a0f527af7ab3a783e1037de86fbcb136ac (diff)
downloadlinux-linaro-stable-15bd1e5cb36306a015328aa1c2b6470a25153171.tar.gz
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "Here are two more driver bugfixes for I2C which would be good to have" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: cadence: Set the hardware time-out register to maximum value i2c: davinci: generate STP always when NACK is received
-rw-r--r--drivers/i2c/busses/i2c-cadence.c11
-rw-r--r--drivers/i2c/busses/i2c-davinci.c8
2 files changed, 14 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index 63f3f03ecc9b..c604f4c3ac0d 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -111,6 +111,8 @@
#define CDNS_I2C_DIVA_MAX 4
#define CDNS_I2C_DIVB_MAX 64
+#define CDNS_I2C_TIMEOUT_MAX 0xFF
+
#define cdns_i2c_readreg(offset) readl_relaxed(id->membase + offset)
#define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset)
@@ -852,6 +854,15 @@ static int cdns_i2c_probe(struct platform_device *pdev)
goto err_clk_dis;
}
+ /*
+ * Cadence I2C controller has a bug wherein it generates
+ * invalid read transaction after HW timeout in master receiver mode.
+ * HW timeout is not used by this driver and the interrupt is disabled.
+ * But the feature itself cannot be disabled. Hence maximum value
+ * is written to this register to reduce the chances of error.
+ */
+ cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
+
dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",
id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq);
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index d15b7c9b9219..01f0cd87a4a5 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -407,11 +407,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
if (msg->flags & I2C_M_IGNORE_NAK)
return msg->len;
- if (stop) {
- w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- w |= DAVINCI_I2C_MDR_STP;
- davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
- }
+ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+ w |= DAVINCI_I2C_MDR_STP;
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
return -EREMOTEIO;
}
return -EIO;