soc/tegra: regulators: Fix locking up when voltage-spread is out of range

commit ef85bb582c41524e9e68dfdbde48e519dac4ab3d upstream.

Fix voltage coupler lockup which happens when voltage-spread is out
of range due to a bug in the code. The max-spread requirement shall be
accounted when CPU regulator doesn't have consumers. This problem is
observed on Tegra30 Ouya game console once system-wide DVFS is enabled
in a device-tree.

Fixes: 783807436f ("soc/tegra: regulators: Add regulators coupler for Tegra30")
Cc: stable@vger.kernel.org
Reported-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Osipenko 2021-03-02 16:18:00 +03:00 committed by Greg Kroah-Hartman
parent 2f2d444ac4
commit a1ad124c83

View File

@ -178,7 +178,7 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
* survive the voltage drop if it's running on a higher frequency.
*/
if (!cpu_min_uV_consumers)
cpu_min_uV = cpu_uV;
cpu_min_uV = max(cpu_uV, cpu_min_uV);
/*
* Bootloader shall set up voltages correctly, but if it