opp: ti-opp-supply: Dynamically update u_volt_min

The voltage range (min, max) provided in the device tree is from
the data manual and is pretty big, catering to a wide range of devices.
On a i2c read/write failure the regulator_set_voltage_triplet function
falls back to set voltage between min and max. The min value from Device
Tree can be lesser than the optimal value and in that case that can lead
to a hang or crash. Hence set the u_volt_min dynamically to the optimal
voltage value.

Cc: 4.16+ <stable@vger.kernel.org> # v4.16+
Fixes: 9a835fa6e47 ("PM / OPP: Add ti-opp-supply driver")
Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/opp/ti-opp-supply.c b/drivers/opp/ti-opp-supply.c
index 9e5a9a3112c9cec57abcffab6c9b23640682756c..29e08a49d13bc00bd8ae424974b73cc9b6090f59 100644 (file)
--- a/drivers/opp/ti-opp-supply.c
+++ b/drivers/opp/ti-opp-supply.c
@@ -290,6 +290,9 @@ static int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
        vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
                                          new_supply_vbb->u_volt);
 
+       if (new_supply_vdd->u_volt_min < vdd_uv)
+               new_supply_vdd->u_volt_min = vdd_uv;
+
        /* Scaling up? Scale voltage before frequency */
        if (freq > old_freq) {
                ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,