Re: [PATCH v1] i2c: imx: fix missing stop condition in single-master mode

From: Stefan Eichenberger <redacted>

A regression was introduced with the implementation of single-master
mode, preventing proper stop conditions from being generated. Devices
that require a valid stop condition, such as EEPROMs, fail to function
correctly as a result.

The issue only affects devices with the single-master property enabled.

This commit resolves the issue by re-enabling I2C bus busy bit (IBB)
polling for single-master mode when generating a stop condition. The fix
further ensures that the i2c_imx->stopped flag is cleared at the start
of each transfer, allowing the stop condition to be correctly generated
in i2c_imx_stop().

According to the reference manual (IMX8MMRM, Rev. 2, 09/2019, page
5270), polling the IBB bit to determine if the bus is free is only
necessary in multi-master mode. Consequently, the IBB bit is not polled
for the start condition in single-master mode.

Fixes: 6692694aca86 ("i2c: imx: do not poll for bus busy in single master mode")
Signed-off-by: Stefan Eichenberger <redacted>
---
 drivers/i2c/busses/i2c-imx.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index f751d231ded8..cbf66a69e20b 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c

@@ -534,20 +534,18 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a
 {
 	unsigned long orig_jiffies = jiffies;
 	unsigned int temp;
-
-	if (!i2c_imx->multi_master)
-		return 0;
+	bool multi_master = i2c_imx->multi_master;