From fcbd4bddb314346a35295701f385b9627bb3a137 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 23 Sep 2016 22:34:41 +0900 Subject: [PATCH] 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 Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-uniphier-f.c | 16 +++++++++++----- 1 file 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 #include +#include #include #include #include @@ -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; } } -- 2.20.1