Hi Mark, On Thu, Jun 6, 2024 at 1:05 PM Mark Brown <broonie@xxxxxxxxxx> wrote: > > On Wed, Jun 05, 2024 at 08:49:33AM +0100, Prabhakar wrote: > > > Driver code flow: > > 1> set regulator to 1.8V (BIT0 = 1) > > 2> Regulator cached state now will be 1.8V > > 3> Now for some reason driver issues a reset to the IP block > > which resets the registers to default value. In this process > > the regulator is set to 3.3V (BIT0 = 0) > > 4> Now the driver requests the regulator core to set 1.8V > > If something is resetting the regulator like this that's a problem in > general, we need to either have the driver notify the core when that > happens so it can reconfigure the regulator or have it reapply > configuration directly. Obviously it's not great to have that happen at > all... > Currently I am seeing this problem with SDHI driver. For the voltage switch operation the MMC core requests the driver to do the change and similarly the MMC core requests the reset operation. > Having the core driver notify the core when that happens so it can reconfigure the regulator or have it reapply configuration directly. Again doing this would be a problem as MMC core also maintains the IOS states, reconfiguring the regulator would cause conflicts between the states. Ulf/Wolfram - please correct me if I'm wrong here. Cheers, Prabhakar
