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If tegra_i2c_mutex_lock() fails, the function returns without calling > pm_runtime_put(), leaking the runtime PM reference acquired by the > preceding pm_runtime_get_sync(). Add the missing pm_runtime_put() > before returning. > > 2. tegra_i2c_mutex_unlock() unconditionally overwrites ret, which may > already hold a transfer error from tegra_i2c_xfer_msg(). If the > transfer failed but the unlock succeeds, the error is silently lost > and the function incorrectly reports success. Use a separate variable > for the unlock return value and preserve error priority: > transfer error > unlock error > message count. > > Fixes: 6077cfd716fb ("i2c: tegra: Add support for SW mutex register") Although this is fixing issues associated with one patch, this is fixing two different issues and so I think that this should be split into 2 patches. > Signed-off-by: Saurav Sachidanand > --- > drivers/i2c/busses/i2c-tegra.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c > index 9fd5ade774a0b..704942d10d69d 100644 > --- a/drivers/i2c/busses/i2c-tegra.c > +++ b/drivers/i2c/busses/i2c-tegra.c > @@ -1656,7 +1656,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], > int num) > { > struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); > - int i, ret; > + int i, ret, ret2; > > ret = pm_runtime_get_sync(i2c_dev->dev); > if (ret < 0) { > @@ -1666,8 +1666,10 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], > } > > ret = tegra_i2c_mutex_lock(i2c_dev); > - if (ret) > + if (ret) { > + pm_runtime_put(i2c_dev->dev); > return ret; > + } > > for (i = 0; i < num; i++) { > enum msg_end_type end_type = MSG_END_STOP; > @@ -1698,10 +1700,10 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], > break; > } > > - ret = tegra_i2c_mutex_unlock(i2c_dev); > + ret2 = tegra_i2c_mutex_unlock(i2c_dev); > pm_runtime_put(i2c_dev->dev); > > - return ret ?: i; > + return ret ?: ret2 ?: i; I can't say I am a fan of this. I wonder if we would be better off removing the return value from tegra_i2c_mutex_unlock() and just WARN if this ever happens? If the unlock did fail, the actual I2C message may still have been sent and the next time we try to send a message I assume that the lock would fail anyway and we would not be able to send further messages. Jon -- nvpublic