On 2018년 11월 22일 03:01, Lukasz Luba wrote:
> The refactoring is needed for the new client in devfreq: suspend.
> To avoid code duplication, move it to the new local function
> devfreq_set_target.
>
> The patch draws on Tobias Jakobi's work posted ~2 years ago, who tried to
> solve issue with devfreq device's frequency during suspend/resume.
> During the discussion on LKML some corner cases and comments appeared
> related to the design. This patch address them keeping in mind suggestions
> from Chanwoo Choi.
As I commented on patch1, please remove it.
>
> Suggested-by: Tobias Jakobi <tjakobi@xxxxxxxxxxxxxxxxxxxxx>
> Suggested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/devfreq/devfreq.c | 62 ++++++++++++++++++++++++++++-------------------
> 1 file changed, 37 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index e20e7e4..cf9c643 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -285,6 +285,42 @@ static int devfreq_notify_transition(struct devfreq *devfreq,
> return 0;
> }
>
> +static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
> + unsigned long *prev_freq, u32 flags)
Please remove the unused space in front of 'unsigned long *prev_freq'.
Use tab only for indentation.
> +{
> + struct devfreq_freqs freqs;
> + unsigned long cur_freq;
> + int err = 0;
> +
> + if (devfreq->profile->get_cur_freq)
> + devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
> + else
> + cur_freq = devfreq->previous_freq;
> +
> + freqs.old = cur_freq;
> + freqs.new = new_freq;
> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
> +
> + err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
> + if (err) {
> + freqs.new = cur_freq;
> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
> + return err;
> + }
> +
> + freqs.new = new_freq;
> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
> +
> + if (devfreq_update_status(devfreq, new_freq))
> + dev_err(&devfreq->dev,
> + "Couldn't update frequency transition information.\n");
> +
> + devfreq->previous_freq = new_freq;
> + *prev_freq = cur_freq;
> +
> + return err;
> +}
> +
> /* Load monitoring helper functions for governors use */
>
> /**
> @@ -296,7 +332,6 @@ static int devfreq_notify_transition(struct devfreq *devfreq,
> */
> int update_devfreq(struct devfreq *devfreq)
> {
> - struct devfreq_freqs freqs;
> unsigned long freq, cur_freq, min_freq, max_freq;
cur_freq is not used after modification. Remove it.
> int err = 0;
> u32 flags = 0;
> @@ -333,31 +368,8 @@ int update_devfreq(struct devfreq *devfreq)
> flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
> }
>
> - if (devfreq->profile->get_cur_freq)
> - devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
> - else
> - cur_freq = devfreq->previous_freq;
> -
> - freqs.old = cur_freq;
> - freqs.new = freq;
> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
> + return devfreq_set_target(devfreq, freq, &cur_freq, flags);
You get the 'cur_freq' from devfreq_set_taget() for devfreq_suspend_device() on patch3.
But, update_devfreq() and devfreq_resume_device() don't use the 'cur_freq' value
from devfreq_set_target().
Instead, getting 'cur_freq' for 'devfreq->resume_freq' in the devfreq_set_target().
Please remove the 'cur_freq' parameter from devfreq_set_target.
>
> - err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
> - if (err) {
> - freqs.new = cur_freq;
> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
> - return err;
> - }
> -
> - freqs.new = freq;
> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
> -
> - if (devfreq_update_status(devfreq, freq))
> - dev_err(&devfreq->dev,
> - "Couldn't update frequency transition information.\n");
> -
> - devfreq->previous_freq = freq;
> - return err;
> }
> EXPORT_SYMBOL(update_devfreq);
>
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
