On Thu, 26 Oct 2017 16:51:13 +0100 Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On Wed, 25 Oct 2017 18:22:02 +0200 > Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > > Hi, > > > > On 25-10-17 18:15, SF Markus Elfring wrote: > > >> IMHO, if you do this, you should rework the function so that there is a single unlock call > > >> at the end, not a separate one in in error label. > > > > > > Thanks for your update suggestion. > > > > > > Does it indicate that I may propose similar source code adjustments > > > in this software area? > > > > > > > > >> Could e.g. change this: > > >> > > >> ret = bmc150_accel_set_power_state(data, false); > > >> mutex_unlock(&data->mutex); > > >> if (ret < 0) > > >> return ret; > > >> > > >> return IIO_VAL_INT; > > >> } > > >> > > >> To: > > >> > > >> ret = bmc150_accel_set_power_state(data, false); > > >> if (ret < 0) > > >> goto unlock; > > >> > > >> ret = IIO_VAL_INT; > > > > If that is the only unlock in the function, then it is probably > > best to keep things as is. In general gotos are considered > > better then multiple unlocks, but not having either is even > > better. > > > > > > > How do you think about to use the following code variant then? > > > > > > if (!ret) > > > ret = IIO_VAL_INT; > > > > > > I believe the goto unlock variant and setting ret = IIO_VAL_INT; > > directly above the unlock label variant is better, because that > > way the error handling is consistent between all steps and if > > another step is later added at the end, the last step will > > not require modification. > I agree, setting ret = IIO_VAL_INT in the good path unconditionally > is good. > > However, it is not just the unlocking that would be nice to > unify here. The call to: > > bmc150_accel_set_power_state(data, false); > > occurs in both the final two error paths and the good path. An > additional label and appropriate gotos would clean that up > as well. Ah my mistake, that would involve 'eating' the first error so isn't a good idea. Ignore this one! Jonathan > > This driver also suffers from issues with racing against > the buffer enable check and buffers being enabled like > I mentioned in the other email. Clearly more cases of > that around than I realised! Patches welcome or I'll suggest > it as an outreachy cleanup task. > > Jonathan > > > > > >> unlock: > > >> mutex_unlock(&data->mutex); > > >> > > >> return ret; > > >> } > > >> > > >> And also use the unlock label in the other cases, this is actually > > >> quite a normal pattern. I see little use in a patch like this if there > > >> are still 2 unlock paths after the patch. > > > > > > How long should I wait for corresponding feedback before another small > > > source code adjustment will be appropriate? > > > > That is hard to say. I usually just do a new version when I've time, > > seldomly someone complains I should have waited longer for feedback > > (when I'm quite quick) but usually sending out a new version as soon > > as you've time to work on a new version is best, since if you wait > > you may then not have time for the entire next week or so, at least > > that is my experience :) There is really no clear rule here. > > > > Regards, > > > > Hans > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
