Re: [PATCH v9 2/8] PM / devfreq: Fix devfreq_notifier_call returning errno
From: Matthias Kaehlcke <mka@chromium.org>
Date: 2019-10-02 21:24:44
Also in:
linux-pm
On Wed, Oct 02, 2019 at 10:25:05PM +0300, Leonard Crestez wrote:
quoted hunk ↗ jump to hunk
Notifier callbacks shouldn't return negative errno but one of the NOTIFY_OK/DONE/BAD values. The OPP core will ignore return values from notifiers but returning a value that matches NOTIFY_STOP_MASK will stop the notification chain. Fix by always returning NOTIFY_OK. Signed-off-by: Leonard Crestez <redacted> --- drivers/devfreq/devfreq.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 7dc899da1172..32bbf6e80380 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c@@ -548,30 +548,32 @@ EXPORT_SYMBOL(devfreq_interval_update); */ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, void *devp) { struct devfreq *devfreq = container_of(nb, struct devfreq, nb); - int ret; + int err = -EINVAL; mutex_lock(&devfreq->lock); devfreq->scaling_min_freq = find_available_min_freq(devfreq); - if (!devfreq->scaling_min_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; - } + if (!devfreq->scaling_min_freq) + goto out; devfreq->scaling_max_freq = find_available_max_freq(devfreq); - if (!devfreq->scaling_max_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; - } + if (!devfreq->scaling_max_freq) + goto out; + + err = update_devfreq(devfreq); - ret = update_devfreq(devfreq); +out: mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from OPP notifier (%d)\n", + err);
In case an OPP freq can't be found the log doesn't provide clues about what the problem could be. I couldn't find a clearly superior errno value though, so I guess this is as good as it gets, unless you want to have a dedicated message for those errors. Should be a rare exception anyway, and previously there was no log at all. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel