On Thu, Jun 06, 2024 at 03:12:42PM +0100, Lad, Prabhakar wrote: > 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. If the device can't cope with the requested configuration being applied why is this going through the regulator API at all? This just seems quite confused, putting a bodge in the core like this clearly isn't the right solution.
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