From: Dmitry Osipenko digetx@gmail.com
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: 783807436f36 ("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 --- drivers/soc/tegra/regulators-tegra30.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/soc/tegra/regulators-tegra30.c +++ b/drivers/soc/tegra/regulators-tegra30.c @@ -178,7 +178,7 @@ static int tegra30_voltage_update(struct * 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