[PATCH v1 09/30] soc/tegra: regulators: Fix lockup when voltage-spread is out of range

Dmitry Osipenko
2020-11-04T23:49:47Z

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
Tested-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/soc/tegra/regulators-tegra30.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/tegra/regulators-tegra30.c b/drivers/soc/tegra/regulators-tegra30.c
index f7a5260edffe..fcf824f73131 100644
--- a/drivers/soc/tegra/regulators-tegra30.c
+++ b/drivers/soc/tegra/regulators-tegra30.c
@@ -198,7 +198,7 @@ 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
--
2.27.0