diff mbox series

thermal: rcar_thermal: Clean up rcar_thermal_update_temp()

Message ID 20200415172349.2185096-1-niklas.soderlund+renesas@ragnatech.se (mailing list archive)
State New, archived
Delegated to: Daniel Lezcano
Headers show
Series thermal: rcar_thermal: Clean up rcar_thermal_update_temp() | expand

Commit Message

Niklas Söderlund April 15, 2020, 5:23 p.m. UTC
Moving the ctemp variable out of the private data structure made it
possible to clean up rcar_thermal_update_temp(). Initialize the local
ctemp to the error code to return if the reading fails and just return
it at the end of the function.

It's OK to change the datatype of old, new and ctemp to int as all
values are AND with CTEMP (0x3f) before being stored. While at it
change the datatype of the loop variable 'i' to to unsigned int.

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
 drivers/thermal/rcar_thermal.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Geert Uytterhoeven April 16, 2020, 8:16 a.m. UTC | #1
Hi Niklas,

On Wed, Apr 15, 2020 at 7:23 PM Niklas Söderlund
<niklas.soderlund+renesas@ragnatech.se> wrote:
> Moving the ctemp variable out of the private data structure made it
> possible to clean up rcar_thermal_update_temp(). Initialize the local
> ctemp to the error code to return if the reading fails and just return
> it at the end of the function.
>
> It's OK to change the datatype of old, new and ctemp to int as all
> values are AND with CTEMP (0x3f) before being stored. While at it

ANDed

> change the datatype of the loop variable 'i' to to unsigned int.
>
> Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

One small suggestion below.

> --- a/drivers/thermal/rcar_thermal.c
> +++ b/drivers/thermal/rcar_thermal.c
> @@ -198,8 +198,8 @@ static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
>  static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
>  {
>         struct device *dev = rcar_priv_to_dev(priv);
> -       int i;
> -       u32 ctemp, old, new;
> +       int old, new, ctemp = -EINVAL;
> +       unsigned int i;
>
>         mutex_lock(&priv->lock);
>
> @@ -209,7 +209,6 @@ static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
>          */
>         rcar_thermal_bset(priv, THSCR, CPCTL, CPCTL);
>
> -       ctemp = 0;
>         old = ~0;
>         for (i = 0; i < 128; i++) {
>                 /*
> @@ -227,7 +226,7 @@ static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
>                 old = new;
>         }
>
> -       if (!ctemp) {
> +       if (ctemp == -EINVAL) {

I think "if (ctemp < 0)" is safer, as it doesn't rely on the actual error code.

>                 dev_err(dev, "thermal sensor was broken\n");
>                 goto err_out_unlock;
>         }
> @@ -248,7 +247,7 @@ static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
>  err_out_unlock:
>         mutex_unlock(&priv->lock);
>
> -       return ctemp ? ctemp : -EINVAL;
> +       return ctemp;
>  }

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
index e0c1f2409035e2bb..3c0c86b0664ec57f 100644
--- a/drivers/thermal/rcar_thermal.c
+++ b/drivers/thermal/rcar_thermal.c
@@ -198,8 +198,8 @@  static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
 static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
 {
 	struct device *dev = rcar_priv_to_dev(priv);
-	int i;
-	u32 ctemp, old, new;
+	int old, new, ctemp = -EINVAL;
+	unsigned int i;
 
 	mutex_lock(&priv->lock);
 
@@ -209,7 +209,6 @@  static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
 	 */
 	rcar_thermal_bset(priv, THSCR, CPCTL, CPCTL);
 
-	ctemp = 0;
 	old = ~0;
 	for (i = 0; i < 128; i++) {
 		/*
@@ -227,7 +226,7 @@  static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
 		old = new;
 	}
 
-	if (!ctemp) {
+	if (ctemp == -EINVAL) {
 		dev_err(dev, "thermal sensor was broken\n");
 		goto err_out_unlock;
 	}
@@ -248,7 +247,7 @@  static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
 err_out_unlock:
 	mutex_unlock(&priv->lock);
 
-	return ctemp ? ctemp : -EINVAL;
+	return ctemp;
 }
 
 static int rcar_thermal_get_current_temp(struct rcar_thermal_priv *priv,