Hi Jacopo,
On 09/04/2020 17:22, Jacopo Mondi wrote:
> Hi Kieran,
> slightly unrelated on this patch but
Everything's related :-) All comments welcome!
>
> On Thu, Apr 09, 2020 at 01:11:52PM +0100, Kieran Bingham wrote:
>> - Fix up cleanup path from GPIO PowerDown registration
>> ---
>> drivers/media/i2c/max9286.c | 14 ++++++++------
>> 1 file changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>> index 0a43137b8112..cc99740b34c5 100644
>> --- a/drivers/media/i2c/max9286.c
>> +++ b/drivers/media/i2c/max9286.c
>> @@ -1171,8 +1171,10 @@ static int max9286_probe(struct i2c_client *client)
>>
>> priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
>> GPIOD_OUT_HIGH);
>> - if (IS_ERR(priv->gpiod_pwdn))
>> - return PTR_ERR(priv->gpiod_pwdn);
>> + if (IS_ERR(priv->gpiod_pwdn)) {
>> + ret = PTR_ERR(priv->gpiod_pwdn);
>> + goto err_cleanup_dt;
>> + }
>>
>> gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
>> gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
>
> As we get_optional(), shouldn't this be protected by an
> if (priv->gpiod_pwdn)
>
> ?
>
Err - yes! That's odd - I was sure I had tested this without a gpio
specifier, and I thought those functions were null-safe, and were a
no-op if there was no desc. Clearly some wire got crossed in my head -
because I see no such null-checks now!
I've added a new squash patch on top to correct for this (including
checking priv->gpiod_pwdn on all uses).
> Another point (sorry, I'm looking at gpio handling only now) we have
> ret = max9286_gpio(priv);
> if (ret)
> return ret;
>
> That's not really a descriptive function name.. Could this be
> max9286_register_gpiochip()
Yup, I'm happy enough to rename that.
Patch added on top.
> ?
>
> One last point and then I'll stop.
>
> We currently do
>
> probe() {
> parse_dt()
>
> pwdn = devm_get_gpio_optional()
> if (err)
> goto err_cleanup_dt()
> set(pwdn, 1);
>
> register_gpiochip(); //uses devm
> goto err_cleanup_dt()
>
> get_regulator()
> goto err_cleanup_dt()
>
> ret = init()
> if (ret)
> goto err_regulator();
>
> return 0
>
> err_regulator:
> regulator_put()
> mux_close()
> i2c_ack_disable()
> err_cleanup_dt:
> cleanup_dt()
>
> }
>
> With patch 5 of this series this becomes
>
> probe() {
> parse_dt()
>
> pwdn = devm_get_gpio_optional()
> if (err)
> goto err_cleanup_dt()
> set(pwdn, 1);
>
> register_gpiochip(); //uses devm
> goto err_cleanup_dt()
>
> devm_get_regulator()
> goto err_cleanup_dt()
>
> ret = init()
> if (ret)
> goto err_regulator();
>
> return 0
>
> err_regulator:
> mux_close()
> i2c_ack_disable()
> err_cleanup_dt:
> cleanup_dt()
> }
>
> as the i2c_mux is already closed at the end of init() (or never open
> if we fail earlier) and i2c_ack can be disabled at the end of
> max9286_setup() and in the error path there (as there are no more i2c
> writes after that function returns), I think we could simplify all of
> thise even more to:
>
> probe() {
> pwdn = devm_get_gpio_optional()
> if (err)
> return;
>
> set(pwdn, 1);
>
> register_gpiochip(); //uses devm
> return;
>
> devm_get_regulator()
> return;
>
> parse_dt()
>
> ret = init()
> if (ret)
> goto cleanup_dt();
>
> return 0
>
> err_cleanup_dt:
> cleanup_dt()
> }
>
> This could be done after 5/5 in this series if you want to keep fixups
> separate for another review round.
>
Yes, indeed - it would make sense where possible to have the devm_
handled constructions before the manually managed ones.
I'll add a patch on top.
> What do you think ?
>
> Thanks
> j
>
>
>
>> @@ -1193,7 +1195,7 @@ static int max9286_probe(struct i2c_client *client)
>> PTR_ERR(priv->regulator));
>> ret = PTR_ERR(priv->regulator);
>> priv->regulator = NULL;
>> - goto err_free;
>> + goto err_cleanup_dt;
>> }
>>
>> /*
>> @@ -1230,7 +1232,7 @@ static int max9286_probe(struct i2c_client *client)
>> regulator_put(priv->regulator);
>> max9286_i2c_mux_close(priv);
>> max9286_configure_i2c(priv, false);
>> -err_free:
>> +err_cleanup_dt:
>> max9286_cleanup_dt(priv);
>>
>> return ret;
>> @@ -1248,10 +1250,10 @@ static int max9286_remove(struct i2c_client *client)
>> regulator_disable(priv->regulator);
>> regulator_put(priv->regulator);
>>
>> - max9286_cleanup_dt(priv);
>> -
>> gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>>
>> + max9286_cleanup_dt(priv);
>> +
>> return 0;
>> }
>>
>> --
>> 2.20.1
>>
