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authorMasahiro Yamada <yamada.masahiro@socionext.com>2016-09-23 22:34:41 +0900
committerWolfram Sang <wsa@the-dreams.de>2016-09-24 11:19:15 +0200
commitfcbd4bddb314346a35295701f385b9627bb3a137 (patch)
tree67bd4016f5d6dcb5659d0c9df82956fd7d79d1cc /drivers/i2c
parent6212e1d6ed4018ae3d3e6079ea0c45df346c97a6 (diff)
downloadlinux-fcbd4bddb314346a35295701f385b9627bb3a137.tar.gz
i2c: uniphier-f: fix misdetection of incomplete STOP condition
Currently, the status register FI2C_SR is checked immediately after a STOP condition is issued in case of the deferred STOP condition. It takes typically 5-10 usec until the corresponding bits in the register are set, so the error check for "stop condition was not completed" is very likely to be false positive. Add wait code to relax the status register check. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-uniphier-f.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c
index 829df91cc759..db9105e52c79 100644
--- a/drivers/i2c/busses/i2c-uniphier-f.c
+++ b/drivers/i2c/busses/i2c-uniphier-f.c
@@ -14,6 +14,7 @@
#include <linux/clk.h>
#include <linux/i2c.h>
+#include <linux/iopoll.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -348,14 +349,19 @@ static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
dev_dbg(&adap->dev, "complete\n");
if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) {
- u32 status = readl(priv->membase + UNIPHIER_FI2C_SR);
-
- if (!(status & UNIPHIER_FI2C_SR_STS) ||
- status & UNIPHIER_FI2C_SR_BB) {
+ u32 status;
+ int ret;
+
+ ret = readl_poll_timeout(priv->membase + UNIPHIER_FI2C_SR,
+ status,
+ (status & UNIPHIER_FI2C_SR_STS) &&
+ !(status & UNIPHIER_FI2C_SR_BB),
+ 1, 20);
+ if (ret) {
dev_err(&adap->dev,
"stop condition was not completed.\n");
uniphier_fi2c_recover(priv);
- return -EBUSY;
+ return ret;
}
}