Hi, On 1/23/21 11:29 AM, Charles Keepax wrote: > On Fri, Jan 22, 2021 at 07:32:50PM +0100, Hans de Goede wrote: >> Sometimes regulator_get() gets called twice for the same supply on the >> same device. This may happen e.g. when a framework / library is used >> which uses the regulator; and the driver itself also needs to enable >> the regulator in some cases where the framework will not enable it. >> >> Commit ff268b56ce8c ("regulator: core: Don't spew backtraces on >> duplicate sysfs") already takes care of the backtrace which would >> trigger when creating a duplicate consumer symlink under >> /sys/class/regulator/regulator.%d in this scenario. >> >> Commit c33d442328f5 ("debugfs: make error message a bit more verbose") >> causes a new error to get logged in this scenario: >> >> [ 26.938425] debugfs: Directory 'wm5102-codec-MICVDD' with parent >> 'spi-WM510204:00-MICVDD' already present! >> >> There is no _nowarn variant of debugfs_create_dir(), but we can detect >> and avoid this problem by checking the return value of the earlier >> sysfs_create_link_nowarn() call. >> >> Add a check for the earlier sysfs_create_link_nowarn() failing with >> -EEXIST and skip the debugfs_create_dir() call in that case, avoiding >> this error getting logged. >> >> Fixes: c33d442328f5 ("debugfs: make error message a bit more verbose") >> Cc: Charles Keepax <ckee...@opensource.cirrus.com> >> Signed-off-by: Hans de Goede <hdego...@redhat.com> >> --- > > Reviewed-by: Charles Keepax <ckee...@opensource.cirrus.com> > > Thanks, > Charles > >> - int err; >> + int err = 0; >> >> @@ -1663,8 +1663,8 @@ static struct regulator *create_regulator(struct >> regulator_dev *rdev, >> >> - regulator->debugfs = debugfs_create_dir(supply_name, >> - rdev->debugfs); >> + if (err != -EEXIST) >> + regulator->debugfs = debugfs_create_dir(supply_name, >> rdev->debugfs); > > There is a slight oddity here in that if this regulator has > no struct device we will still get the warning. However, I > am totally not clear on when/why a regulator might not have a > dev, and am fairly sure it isn't common. So my vote would be > to cross that bridge if we ever come to it.
Yes, I expect the combination of having 2 consumers which both get the regulator with a NULL device pointer to be very rare and hopefully it does not happen at all. Regards, Hans