The spec is from 1.7V to 1.95V, with 1.8V being ideal. It's not that symmetric. But let's say that 0.1V is fine for tolerance(so 1.7-1.9V) regulator_set_voltage_tol looks interesting, but i still think it's not the appropriate thing to use in this case. Imagine a board has a 1V-1.79 V regulator, we tell it to regulator_set_voltage_tol(1800000,100000). It will try the 1.8V-1.9V range, when it sees that it can't it'll fallback to 1.7V - 1.9V, and it will just be lazy and pick the lowest of the range again: 1.7V(causing voltage drop issues because we're exactly at the minimum of the spec). The correct voltage would be 1.79V It's unfortunate that regulator_set_voltage was designed to always pick the lowest voltage in that range. I understand that it's a power efficiency thing, but it's not ideal in cases like this. Alexandru Stan (amstan) On Wed, Dec 10, 2014 at 3:53 PM, Mark Brown <broonie at kernel.org> wrote: > On Wed, Dec 10, 2014 at 12:58:02PM -0800, Doug Anderson wrote: >> There are some cases where you'd like to set a voltage for a regulator >> and a range of voltages are OK, but you'd really like to get as close >> as you can to a specific voltage if at all possible. > > This looks like regulator_set_voltage_tol(), why not use that? The spec > probably even has a number for the tolerance, or you can make one up.
