i2c: npcm7xx: Fix timeout calculation

timeout_usec value calculation was wrong, the calculated value
was in msec instead of usec.

Fixes: 56a1485b102e ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Reviewed-by: Avi Fishman <avifishman70@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Alex Qiu <xqiu@google.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 75f0713..dfcf04e 100644 (file)
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2093,8 +2093,12 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
                }
        }
 
-       /* Adaptive TimeOut: astimated time in usec + 100% margin */
-       timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite);
+       /*
+        * Adaptive TimeOut: estimated time in usec + 100% margin:
+        * 2: double the timeout for clock stretching case
+        * 9: bits per transaction (including the ack/nack)
+        */
+       timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
        timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec));
        if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
                dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);