[PATCH 3/3] regulator: bd718x7: Use dev_err_probe()

From: Matti Vaittinen
Date: Wed Nov 23 2022 - 07:00:50 EST


The dev_err_probe() has (at least) following benefits over dev_err()
when printing an error print for a failed function call at a device
driver probe:
- Omit error level print if error is 'EPRBE_DEFER'
- Standardized print format for returned error
- return the error value allowing shortening calls like:

if (ret) {
dev_err(...);
return ret;
}

to

if (ret)
return dev_err_probe(...);

Convert the ROHM BD718x7 regulator driver to use the dev_err_probe() when
returned error is not hard-coded constant.

NOTE:
This commit also changes the error handling path to return immediately
from a spot where the error is spotted instead of using a single point
of exit.

Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>

---
For many years I have preferred a single point of exit in a function
when managing it does not require any big tricks. In my experience a
single point of exit makes resource-leaking and lock releasing much less
error prone. Eg, consider mistakes like:

...
mutex_lock(&mtx)
...
if (err)
return err;
...
mutex_unlock(&mtx);

return 0;

Vs.

...
mutex_lock(&mtx)
...
if (err)
goto err_out;
...

err_out:
mutex_unlock(&mtx);

return err;

I still think a single point of exit is often a good idea. However, I am
slowly adapting to thought that the single point of exit does not really
play a big role in bd718x7 regulator probe and using dev_err_probe()
allows us to avoid the extra {} after condition... So, maybe it indeed
is a time for me to ditch the goto here. Please, let me know if you
think othervice :)
---
drivers/regulator/bd718x7-regulator.c | 51 ++++++++++-----------------
1 file changed, 19 insertions(+), 32 deletions(-)

diff --git a/drivers/regulator/bd718x7-regulator.c b/drivers/regulator/bd718x7-regulator.c
index d161b0026f33..894fab0d53d0 100644
--- a/drivers/regulator/bd718x7-regulator.c
+++ b/drivers/regulator/bd718x7-regulator.c
@@ -1706,20 +1706,17 @@ static int bd718xx_probe(struct platform_device *pdev)
break;
default:
dev_err(&pdev->dev, "Unsupported chip type\n");
- err = -EINVAL;
- goto err;
+ return -EINVAL;
}

/* Register LOCK release */
err = regmap_update_bits(regmap, BD718XX_REG_REGLOCK,
(REGLOCK_PWRSEQ | REGLOCK_VREG), 0);
- if (err) {
- dev_err(&pdev->dev, "Failed to unlock PMIC (%d)\n", err);
- goto err;
- } else {
- dev_dbg(&pdev->dev, "Unlocked lock register 0x%x\n",
- BD718XX_REG_REGLOCK);
- }
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "Failed to unlock PMIC\n");
+
+ dev_dbg(&pdev->dev, "Unlocked lock register 0x%x\n",
+ BD718XX_REG_REGLOCK);

use_snvs = of_property_read_bool(pdev->dev.parent->of_node,
"rohm,reset-snvs-powered");
@@ -1736,13 +1733,11 @@ static int bd718xx_probe(struct platform_device *pdev)
BD718XX_WDOG_POWEROFF_MASK |
BD718XX_KEY_L_POWEROFF_MASK,
BD718XX_POWOFF_TO_RDY);
- if (err) {
- dev_err(&pdev->dev, "Failed to change reset target\n");
- goto err;
- } else {
- dev_dbg(&pdev->dev,
- "Changed all resets from SVNS to READY\n");
- }
+ if (err)
+ return dev_err_probe(&pdev->dev, err,
+ "Failed to change reset target\n");
+
+ dev_dbg(&pdev->dev, "Changed all resets from SVNS to READY\n");
}

config.dev = pdev->dev.parent;
@@ -1778,13 +1773,10 @@ static int bd718xx_probe(struct platform_device *pdev)
desc->ops = swops[i];

rdev = devm_regulator_register(&pdev->dev, desc, &config);
- if (IS_ERR(rdev)) {
- dev_err(&pdev->dev,
- "failed to register %s regulator\n",
- desc->name);
- err = PTR_ERR(rdev);
- goto err;
- }
+ if (IS_ERR(rdev))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rdev),
+ "failed to register %s regulator\n",
+ desc->name);

/*
* Regulator register gets the regulator constraints and
@@ -1807,28 +1799,23 @@ static int bd718xx_probe(struct platform_device *pdev)
!rdev->constraints->boot_on)) {
err = regmap_update_bits(regmap, r->init.reg,
r->init.mask, r->init.val);
- if (err) {
- dev_err(&pdev->dev,
+ if (err)
+ return dev_err_probe(&pdev->dev, err,
"Failed to take control for (%s)\n",
desc->name);
- goto err;
- }
}
for (j = 0; j < r->additional_init_amnt; j++) {
err = regmap_update_bits(regmap,
r->additional_inits[j].reg,
r->additional_inits[j].mask,
r->additional_inits[j].val);
- if (err) {
- dev_err(&pdev->dev,
+ if (err)
+ return dev_err_probe(&pdev->dev, err,
"Buck (%s) initialization failed\n",
desc->name);
- goto err;
- }
}
}

-err:
return err;
}

--
2.38.1


--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]

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