4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fabio Estevam <fabio.estevam@xxxxxxx> commit fc12bccda8b6f5c38139eceec9e369ed78091b2b upstream. Commit deb65870b5d9d ("drm/imx: imx-tve: check the value returned by regulator_set_voltage()") exposes the following probe issue: 63ff0000.tve supply dac not found, using dummy regulator imx-drm display-subsystem: failed to bind 63ff0000.tve (ops imx_tve_ops): -22 When the 'dac-supply' is not passed in the device tree a dummy regulator is used and setting its voltage is not allowed. To fix this issue, do not set the dac-supply voltage inside the driver and let its voltage be specified in the device tree. Print a warning if the the 'dac-supply' voltage has a value different from 2.75V. Fixes: deb65870b5d9d ("drm/imx: imx-tve: check the value returned by regulator_set_voltage()") Suggested-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/imx/imx-tve.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/imx/imx-tve.c +++ b/drivers/gpu/drm/imx/imx-tve.c @@ -98,6 +98,8 @@ /* TVE_TST_MODE_REG */ #define TVE_TVDAC_TEST_MODE_MASK (0x7 << 0) +#define IMX_TVE_DAC_VOLTAGE 2750000 + enum { TVE_MODE_TVOUT, TVE_MODE_VGA, @@ -621,9 +623,8 @@ static int imx_tve_bind(struct device *d tve->dac_reg = devm_regulator_get(dev, "dac"); if (!IS_ERR(tve->dac_reg)) { - ret = regulator_set_voltage(tve->dac_reg, 2750000, 2750000); - if (ret) - return ret; + if (regulator_get_voltage(tve->dac_reg) != IMX_TVE_DAC_VOLTAGE) + dev_warn(dev, "dac voltage is not %d uV\n", IMX_TVE_DAC_VOLTAGE); ret = regulator_enable(tve->dac_reg); if (ret) return ret;