Re: [PATCH 1/1] staging: ti-soc-thermal: remove usage of IS_ERR_OR_NULL

From: Eduardo Valentin
Date: Thu Apr 25 2013 - 16:17:09 EST


Russell,

Thanks for your time reviewing this patch.

On 25-04-2013 13:44, Russell King wrote:
On Thu, Apr 25, 2013 at 09:46:16AM -0400, Eduardo Valentin wrote:
diff --git a/drivers/staging/ti-soc-thermal/ti-bandgap.c b/drivers/staging/ti-soc-thermal/ti-bandgap.c
index f20c1cf..5027833 100644
--- a/drivers/staging/ti-soc-thermal/ti-bandgap.c
+++ b/drivers/staging/ti-soc-thermal/ti-bandgap.c
@@ -469,7 +469,7 @@ static inline int ti_bandgap_validate(struct ti_bandgap *bgp, int id)
{
int ret = 0;

- if (IS_ERR_OR_NULL(bgp)) {
+ if (!bgp || IS_ERR(bgp)) {
pr_err("%s: invalid bandgap pointer\n", __func__);
ret = -EINVAL;

We really don't need these kinds of "bad pointer passed to a function"
checks in the kernel. Just ensure that all callers have correctly
error checked the return value.

Right.. I will check if it is safe to simply remove the above check.


goto exit;
@@ -1191,7 +1191,7 @@ int ti_bandgap_probe(struct platform_device *pdev)
int clk_rate, ret = 0, i;

bgp = ti_bandgap_build(pdev);
- if (IS_ERR_OR_NULL(bgp)) {
+ if (IS_ERR(bgp)) {
dev_err(&pdev->dev, "failed to fetch platform data\n");
return PTR_ERR(bgp);

That was definitely a bug, good fix.

}
@@ -1207,14 +1207,14 @@ int ti_bandgap_probe(struct platform_device *pdev)
}

bgp->fclock = clk_get(NULL, bgp->conf->fclock_name);
- ret = IS_ERR_OR_NULL(bgp->fclock);
+ ret = IS_ERR(bgp->fclock);
if (ret) {
dev_err(&pdev->dev, "failed to request fclock reference\n");
goto free_irqs;
}

I'm not sure that's correct. If free_irqs ends up returning 'ret' then
it will return 0 or 1, not the error code.

Indeed. Good point.


if (IS_ERR(bgp->fclock)) {
dev_err...
ret = PTR_ERR(bgp->fclock);
goto free_irqs;
}

would be much better in that case.

Yes, I will incorporate the above on next version.


Also another fix - clk_get(&pdev->dev, "fclk") and arrange for the
clkdev settings for this device. Same for the one below but call
it "div_clk" or something.

Yeh, that may come in a separated patch. I believe the driver just follows the TI OMAP autogeneration design. It just fetches the clk name fro hw database and auto gen the clkdev settings, I believe.



bgp->div_clk = clk_get(NULL, bgp->conf->div_ck_name);
- ret = IS_ERR_OR_NULL(bgp->div_clk);
+ ret = IS_ERR(bgp->div_clk);
if (ret) {

Possibly the same problem here if 'ret' ends up being returned as-is.

agreed.


diff --git a/drivers/staging/ti-soc-thermal/ti-thermal-common.c b/drivers/staging/ti-soc-thermal/ti-thermal-common.c
index 8e67ebf..4c5f55c37 100644
--- a/drivers/staging/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/staging/ti-soc-thermal/ti-thermal-common.c
@@ -101,7 +101,7 @@ static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,

pcb_tz = data->pcb_tz;
/* In case pcb zone is available, use the extrapolation rule with it */
- if (!IS_ERR_OR_NULL(pcb_tz)) {
+ if (!IS_ERR(pcb_tz)) {
ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
if (!ret) {
tmp -= pcb_temp; /* got a valid PCB temp */
@@ -124,7 +124,7 @@ static int ti_thermal_bind(struct thermal_zone_device *thermal,
struct ti_thermal_data *data = thermal->devdata;
int id;

- if (IS_ERR_OR_NULL(data))
+ if (!data || IS_ERR(data))
return -ENODEV;

/* check if this is the cooling device we registered */
@@ -146,7 +146,7 @@ static int ti_thermal_unbind(struct thermal_zone_device *thermal,
{
struct ti_thermal_data *data = thermal->devdata;

- if (IS_ERR_OR_NULL(data))
+ if (!data || IS_ERR(data))
return -ENODEV;

/* check if this is the cooling device we registered */
@@ -282,6 +282,7 @@ static struct ti_thermal_data
data->sensor_id = id;
data->bgp = bgp;
data->mode = THERMAL_DEVICE_ENABLED;
+ /* pcb_tz will be either valid or PTR_ERR() */
data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
INIT_WORK(&data->thermal_wq, ti_thermal_work);

@@ -295,7 +296,7 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,

data = ti_bandgap_get_sensor_data(bgp, id);

- if (IS_ERR_OR_NULL(data))
+ if (!data || IS_ERR(data))
data = ti_thermal_build_data(bgp, id);

if (!data)
@@ -306,7 +307,7 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,
NULL, FAST_TEMP_MONITORING_RATE,
FAST_TEMP_MONITORING_RATE);
- if (IS_ERR_OR_NULL(data->ti_thermal)) {
+ if (IS_ERR(data->ti_thermal)) {
dev_err(bgp->dev, "thermal zone device is NULL\n");
return PTR_ERR(data->ti_thermal);
}
@@ -343,7 +344,7 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
struct ti_thermal_data *data;

data = ti_bandgap_get_sensor_data(bgp, id);
- if (IS_ERR_OR_NULL(data))
+ if (!data || IS_ERR(data))
data = ti_thermal_build_data(bgp, id);

I can't tell whether the above are correct or not as I can't see the
original code.


That is in staging/next.



if (!data)
@@ -356,7 +357,7 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)

/* Register cooling device */
data->cool_dev = cpufreq_cooling_register(cpu_present_mask);
- if (IS_ERR_OR_NULL(data->cool_dev)) {
+ if (IS_ERR(data->cool_dev)) {
dev_err(bgp->dev,
"Failed to register cpufreq cooling device\n");
return PTR_ERR(data->cool_dev);

Definitely a bug - and another good fix.

Thanks.


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