From: Enric Balletbo i Serra enric.balletbo@collabora.com
[ Upstream commit e9153311491da9d9863ead9888a1613531cb4a1b ]
`cat /sys/kernel/debug/regulator/regulator_summary` ends on a deadlock when you have a voltage controlled regulator (vctrl).
The problem is that the vctrl_get_voltage() and vctrl_set_voltage() calls the regulator_get_voltage() and regulator_set_voltage() and that will try to lock again the dependent regulators (the regulator supplying the control voltage).
Fix the issue by exporting the unlocked version of the regulator_get_voltage() and regulator_set_voltage() API so drivers that need it, like the voltage controlled regulator driver can use it.
Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Reported-by: Douglas Anderson dianders@chromium.org Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Link: https://lore.kernel.org/r/20200116094543.2847321-1-enric.balletbo@collabora.... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/core.c | 2 ++ drivers/regulator/vctrl-regulator.c | 38 +++++++++++++++++------------ 2 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 1dba0bdf37623..c6fa0f4451aeb 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -3462,6 +3462,7 @@ int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV, out: return ret; } +EXPORT_SYMBOL(regulator_set_voltage_rdev);
static int regulator_limit_voltage_step(struct regulator_dev *rdev, int *current_uV, int *min_uV) @@ -4026,6 +4027,7 @@ int regulator_get_voltage_rdev(struct regulator_dev *rdev) return ret; return ret - rdev->constraints->uV_offset; } +EXPORT_SYMBOL(regulator_get_voltage_rdev);
/** * regulator_get_voltage - get regulator output voltage diff --git a/drivers/regulator/vctrl-regulator.c b/drivers/regulator/vctrl-regulator.c index 9a9ee81881098..cbadb1c996790 100644 --- a/drivers/regulator/vctrl-regulator.c +++ b/drivers/regulator/vctrl-regulator.c @@ -11,10 +11,13 @@ #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/regulator/coupler.h> #include <linux/regulator/driver.h> #include <linux/regulator/of_regulator.h> #include <linux/sort.h>
+#include "internal.h" + struct vctrl_voltage_range { int min_uV; int max_uV; @@ -79,7 +82,7 @@ static int vctrl_calc_output_voltage(struct vctrl_data *vctrl, int ctrl_uV) static int vctrl_get_voltage(struct regulator_dev *rdev) { struct vctrl_data *vctrl = rdev_get_drvdata(rdev); - int ctrl_uV = regulator_get_voltage(vctrl->ctrl_reg); + int ctrl_uV = regulator_get_voltage_rdev(vctrl->ctrl_reg->rdev);
return vctrl_calc_output_voltage(vctrl, ctrl_uV); } @@ -90,16 +93,16 @@ static int vctrl_set_voltage(struct regulator_dev *rdev, { struct vctrl_data *vctrl = rdev_get_drvdata(rdev); struct regulator *ctrl_reg = vctrl->ctrl_reg; - int orig_ctrl_uV = regulator_get_voltage(ctrl_reg); + int orig_ctrl_uV = regulator_get_voltage_rdev(ctrl_reg->rdev); int uV = vctrl_calc_output_voltage(vctrl, orig_ctrl_uV); int ret;
if (req_min_uV >= uV || !vctrl->ovp_threshold) /* voltage rising or no OVP */ - return regulator_set_voltage( - ctrl_reg, + return regulator_set_voltage_rdev(ctrl_reg->rdev, vctrl_calc_ctrl_voltage(vctrl, req_min_uV), - vctrl_calc_ctrl_voltage(vctrl, req_max_uV)); + vctrl_calc_ctrl_voltage(vctrl, req_max_uV), + PM_SUSPEND_ON);
while (uV > req_min_uV) { int max_drop_uV = (uV * vctrl->ovp_threshold) / 100; @@ -114,9 +117,10 @@ static int vctrl_set_voltage(struct regulator_dev *rdev, next_uV = max_t(int, req_min_uV, uV - max_drop_uV); next_ctrl_uV = vctrl_calc_ctrl_voltage(vctrl, next_uV);
- ret = regulator_set_voltage(ctrl_reg, + ret = regulator_set_voltage_rdev(ctrl_reg->rdev, + next_ctrl_uV, next_ctrl_uV, - next_ctrl_uV); + PM_SUSPEND_ON); if (ret) goto err;
@@ -130,7 +134,8 @@ static int vctrl_set_voltage(struct regulator_dev *rdev,
err: /* Try to go back to original voltage */ - regulator_set_voltage(ctrl_reg, orig_ctrl_uV, orig_ctrl_uV); + regulator_set_voltage_rdev(ctrl_reg->rdev, orig_ctrl_uV, orig_ctrl_uV, + PM_SUSPEND_ON);
return ret; } @@ -155,9 +160,10 @@ static int vctrl_set_voltage_sel(struct regulator_dev *rdev,
if (selector >= vctrl->sel || !vctrl->ovp_threshold) { /* voltage rising or no OVP */ - ret = regulator_set_voltage(ctrl_reg, + ret = regulator_set_voltage_rdev(ctrl_reg->rdev, + vctrl->vtable[selector].ctrl, vctrl->vtable[selector].ctrl, - vctrl->vtable[selector].ctrl); + PM_SUSPEND_ON); if (!ret) vctrl->sel = selector;
@@ -173,9 +179,10 @@ static int vctrl_set_voltage_sel(struct regulator_dev *rdev, else next_sel = vctrl->vtable[vctrl->sel].ovp_min_sel;
- ret = regulator_set_voltage(ctrl_reg, + ret = regulator_set_voltage_rdev(ctrl_reg->rdev, vctrl->vtable[next_sel].ctrl, - vctrl->vtable[next_sel].ctrl); + vctrl->vtable[next_sel].ctrl, + PM_SUSPEND_ON); if (ret) { dev_err(&rdev->dev, "failed to set control voltage to %duV\n", @@ -195,9 +202,10 @@ static int vctrl_set_voltage_sel(struct regulator_dev *rdev, err: if (vctrl->sel != orig_sel) { /* Try to go back to original voltage */ - if (!regulator_set_voltage(ctrl_reg, + if (!regulator_set_voltage_rdev(ctrl_reg->rdev, + vctrl->vtable[orig_sel].ctrl, vctrl->vtable[orig_sel].ctrl, - vctrl->vtable[orig_sel].ctrl)) + PM_SUSPEND_ON)) vctrl->sel = orig_sel; else dev_warn(&rdev->dev, @@ -482,7 +490,7 @@ static int vctrl_probe(struct platform_device *pdev) if (ret) return ret;
- ctrl_uV = regulator_get_voltage(vctrl->ctrl_reg); + ctrl_uV = regulator_get_voltage_rdev(vctrl->ctrl_reg->rdev); if (ctrl_uV < 0) { dev_err(&pdev->dev, "failed to get control voltage\n"); return ctrl_uV;