Messages in this thread | | | Date | Wed, 30 Jun 2021 08:54:16 +0200 | From | Mauro Carvalho Chehab <> | Subject | Re: [PATCH] regulator: hi6421v600: Fix setting wrong driver_data |
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Em Tue, 22 Jun 2021 12:33:29 +0800 Axel Lin <axel.lin@ingics.com> escreveu:
> Current code set "config.driver_data = sreg" but sreg only init the mutex, > the othere fields are just zero. Fix it by pass *info to config.driver_data > so each regulator can get corresponding data by rdev_get_drvdata(). > > Separate enable_mutex from struct hi6421_spmi_reg_info since only need one > mutex for the driver. > > Fixes: d2dfd50a0b57 ("staging: hikey9xx: hi6421v600-regulator: move LDO config from DT") > Signed-off-by: Axel Lin <axel.lin@ingics.com>
As discussed on a separate thread, this patch is broken. See below.
> --- > drivers/regulator/hi6421v600-regulator.c | 26 ++++++++++++++---------- > 1 file changed, 15 insertions(+), 11 deletions(-) > > diff --git a/drivers/regulator/hi6421v600-regulator.c b/drivers/regulator/hi6421v600-regulator.c > index b5a19938fd3a..21153ee03a3f 100644 > --- a/drivers/regulator/hi6421v600-regulator.c > +++ b/drivers/regulator/hi6421v600-regulator.c > @@ -16,13 +16,15 @@ > #include <linux/regulator/driver.h> > #include <linux/spmi.h> > > +struct hi6421_spmi_reg_priv { > + /* Serialize regulator enable logic */ > + struct mutex enable_mutex; > +}; > + > struct hi6421_spmi_reg_info { > struct regulator_desc desc; > u8 eco_mode_mask; > u32 eco_uA; > - > - /* Serialize regulator enable logic */ > - struct mutex enable_mutex; > }; > > static const unsigned int ldo3_voltages[] = { > @@ -96,11 +98,12 @@ static const unsigned int ldo34_voltages[] = { > > static int hi6421_spmi_regulator_enable(struct regulator_dev *rdev) > { > - struct hi6421_spmi_reg_info *sreg = rdev_get_drvdata(rdev); > + struct hi6421_spmi_reg_priv *priv; > int ret; > > + priv = dev_get_drvdata(rdev->dev.parent); > /* cannot enable more than one regulator at one time */ > - mutex_lock(&sreg->enable_mutex); > + mutex_lock(&priv->enable_mutex); > > ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg, > rdev->desc->enable_mask, > @@ -109,7 +112,7 @@ static int hi6421_spmi_regulator_enable(struct regulator_dev *rdev) > /* Avoid powering up multiple devices at the same time */ > usleep_range(rdev->desc->off_on_delay, rdev->desc->off_on_delay + 60); > > - mutex_unlock(&sreg->enable_mutex); > + mutex_unlock(&priv->enable_mutex); > > return ret; > } > @@ -225,7 +228,7 @@ static int hi6421_spmi_regulator_probe(struct platform_device *pdev) > { > struct device *pmic_dev = pdev->dev.parent; > struct regulator_config config = { }; > - struct hi6421_spmi_reg_info *sreg; > + struct hi6421_spmi_reg_priv *priv; > struct hi6421_spmi_reg_info *info; > struct device *dev = &pdev->dev; > struct hi6421_spmi_pmic *pmic; > @@ -241,17 +244,18 @@ static int hi6421_spmi_regulator_probe(struct platform_device *pdev) > if (WARN_ON(!pmic)) > return -ENODEV; > > - sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL); > - if (!sreg) > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > return -ENOMEM; > > - mutex_init(&sreg->enable_mutex); > + mutex_init(&priv->enable_mutex); > + platform_set_drvdata(pdev, priv); > > for (i = 0; i < ARRAY_SIZE(regulator_info); i++) { > info = ®ulator_info[i]; > > config.dev = pdev->dev.parent;
This is the main problem of this patch. See, pdev->dev.parent is actually the device's parent (e. g. the SPMI controller's device).
Looking at (devm_)regulator_register() implementation, it uses it to store the rdev->dev.parent:
struct regulator_dev * regulator_register(const struct regulator_desc *regulator_desc, const struct regulator_config *cfg) { ...
dev = cfg->dev; ... rdev->dev.parent = dev;
So, while you used platform_set_drvdata() to set the data for the regulator's platform driver, when the driver tries to access the mutex, the code does, instead:
static int hi6421_spmi_regulator_enable(struct regulator_dev *rdev) { struct hi6421_spmi_reg_info *sreg = rdev_get_drvdata(rdev); struct hi6421_spmi_reg_priv *priv; int ret; priv = dev_get_drvdata(rdev->dev.parent);
mutex_lock(&priv->enable_mutex);
At this point, priv will be set to the value of the SPMI controller dev data, instead of pointing to the area stored via platform_set_drvdata().
As the data stored there is not the enable_mutex, a call to mutex_lock() makes the device to hang at boot time (or to cause some other random issue, as it is using a different memory than what it was expected).
Thanks, Mauro
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