On Wed, Apr 19, 2023 at 05:23:55PM +0300, Dan Carpenter wrote:
> The return -ERANGE error paths need to call mutex_unlock(&priv->lock);
> before returning.
>
> Fixes: 25d21447d896 ("counter: Add Renesas RZ/G2L MTU3a counter driver")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
The changes in this patch are for rz_mtu3_count_ceiling_write(), so the
title of this patch should be fixed.
> ---
> drivers/counter/rz-mtu3-cnt.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/counter/rz-mtu3-cnt.c b/drivers/counter/rz-mtu3-cnt.c
> index a371bab68499..aeadce5e2853 100644
> --- a/drivers/counter/rz-mtu3-cnt.c
> +++ b/drivers/counter/rz-mtu3-cnt.c
> @@ -358,19 +358,23 @@ static int rz_mtu3_count_ceiling_write(struct counter_device *counter,
> switch (count->id) {
> case RZ_MTU3_16_BIT_MTU1_CH:
> case RZ_MTU3_16_BIT_MTU2_CH:
> - if (ceiling > U16_MAX)
> - return -ERANGE;
> + if (ceiling > U16_MAX) {
> + ret = -ERANGE;
> + goto unlock;
> + }
> priv->mtu_16bit_max[ch_id] = ceiling;
> break;
> case RZ_MTU3_32_BIT_CH:
> - if (ceiling > U32_MAX)
> - return -ERANGE;
> + if (ceiling > U32_MAX) {
> + ret = -ERANGE;
> + goto unlock;
> + }
> priv->mtu_32bit_max = ceiling;
> break;
> default:
> /* should never reach this path */
> - mutex_unlock(&priv->lock);
> - return -EINVAL;
> + ret = -EINVAL;
> + goto unlock;
> }
Normally, I like "goto unlock" patterns, but I think in this context it
makes the flow of code confusing with the mix-match of the switch cases;
default case jumps with a goto, but RZ_MTU3_* cases passes will break,
yet RZ_MUT3_* failures have a goto path. Rather than a "goto unlock"
pattern, I'd prefer to see simply mutex_lock() called for these ceiling
checks. That also has the benefit of reducing the number of changes we
have to make for this fix.
William Breathitt Gray
>
> pm_runtime_get_sync(ch->dev);
> @@ -381,9 +385,9 @@ static int rz_mtu3_count_ceiling_write(struct counter_device *counter,
>
> rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR, RZ_MTU3_TCR_CCLR_TGRA);
> pm_runtime_put(ch->dev);
> +unlock:
> mutex_unlock(&priv->lock);
> -
> - return 0;
> + return ret;
> }
>
> static void rz_mtu3_32bit_cnt_setting(struct counter_device *counter)
> --
> 2.39.2
>
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