On Mon, Oct 14, 2019 at 12:49:07PM +0200, Jean-Jacques Hiblot wrote: > > On 13/10/2019 14:09, Pavel Machek wrote: > > Hi! > > > > > I must say I'm not a big fan of this change. > > > It adds a bunch of code to the LED core and gives small > > > functionality in a reward. It may also influence maximum > > > software blinking rate, so I'd rather avoid calling > > > regulator_enable/disable when timer trigger is set. > > > > > > It will of course require more code. > > > > > > Since AFAIR Pavel was original proponent of this change then > > > I'd like to see his opinion before we move on to discussing > > > possible improvements to this patch. > > Was I? > > > > Okay, this series looks quite confusing to me. First, 1/3 looks > > "interesting" (would have to analyze it way more). > > > > Second, 3/3... So we have a LED driver _and_ a regulator? So yes, the > > chip driving a LED is usually ... voltage/current regulator. What is > > second regulator doing there? Is that a common setup? > > This is quite common with current-sink LED drivers. > > The setup looks like this: > > +-----------+ > | | > | Regulator | > | +------------------------+ > | | | > +-----------+ __|__ > \ / > +---------------------+ \ / led > | | V > | Led Driver | --+-- > | | | > | | | > | +----------+ > | \ | > | \ | > | + | > | | | > +---------------------+ > | > +--+--+ > /////// > > > Only the regulator usually does not supply only one LED. Given questions have been raised about the complexity of the change I wondered whether, for a system with this topology, the regulator could/should be enabled when the LED driver driver probes? Daniel.
