Currently when setting a frequency in panfrost_devfreq_target the
returned frequency is the actual frequency that the clock driver reports
(the return of clk_get_rate()). However, where the provided OPPs don't
precisely match the frequencies that the clock actually achieves devfreq
will then complain (repeatedly):
devfreq devfreq0: Couldn't update frequency transition information.
To avoid this change panfrost_devfreq_target() to fetch the opp using
devfreq_recommened_opp() and not actually query the clock for the
frequency.
A similar problem exists with panfrost_devfreq_get_cur_freq(), but in
this case because the function is optional we can just remove it and
devfreq will fall back to using the previously set frequency.
Fixes: 221bc77914cb ("drm/panfrost: Use generic code for devfreq")
Signed-off-by: Steven Price <[email protected]>
---
drivers/gpu/drm/panfrost/panfrost_devfreq.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 4c4e8a30a1ac..536ba93b0f46 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -18,15 +18,18 @@ static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev);
static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
u32 flags)
{
- struct panfrost_device *pfdev = dev_get_drvdata(dev);
+ struct dev_pm_opp *opp;
int err;
+ opp = devfreq_recommended_opp(dev, freq, flags);
+ if (IS_ERR(opp))
+ return PTR_ERR(opp);
+ dev_pm_opp_put(opp);
+
err = dev_pm_opp_set_rate(dev, *freq);
if (err)
return err;
- *freq = clk_get_rate(pfdev->clock);
-
return 0;
}
@@ -60,20 +63,10 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
return 0;
}
-static int panfrost_devfreq_get_cur_freq(struct device *dev, unsigned long *freq)
-{
- struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev));
-
- *freq = clk_get_rate(pfdev->clock);
-
- return 0;
-}
-
static struct devfreq_dev_profile panfrost_devfreq_profile = {
.polling_ms = 50, /* ~3 frames */
.target = panfrost_devfreq_target,
.get_dev_status = panfrost_devfreq_get_dev_status,
- .get_cur_freq = panfrost_devfreq_get_cur_freq,
};
int panfrost_devfreq_init(struct panfrost_device *pfdev)
--
2.20.1
Reviewed-by: Alyssa Rosenzweig <[email protected]>
On Mon, Nov 18, 2019 at 05:30:02PM +0000, Steven Price wrote:
> Currently when setting a frequency in panfrost_devfreq_target the
> returned frequency is the actual frequency that the clock driver reports
> (the return of clk_get_rate()). However, where the provided OPPs don't
> precisely match the frequencies that the clock actually achieves devfreq
> will then complain (repeatedly):
>
> devfreq devfreq0: Couldn't update frequency transition information.
>
> To avoid this change panfrost_devfreq_target() to fetch the opp using
> devfreq_recommened_opp() and not actually query the clock for the
> frequency.
>
> A similar problem exists with panfrost_devfreq_get_cur_freq(), but in
> this case because the function is optional we can just remove it and
> devfreq will fall back to using the previously set frequency.
>
> Fixes: 221bc77914cb ("drm/panfrost: Use generic code for devfreq")
> Signed-off-by: Steven Price <[email protected]>
> ---
> drivers/gpu/drm/panfrost/panfrost_devfreq.c | 19 ++++++-------------
> 1 file changed, 6 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 4c4e8a30a1ac..536ba93b0f46 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -18,15 +18,18 @@ static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev);
> static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
> u32 flags)
> {
> - struct panfrost_device *pfdev = dev_get_drvdata(dev);
> + struct dev_pm_opp *opp;
> int err;
>
> + opp = devfreq_recommended_opp(dev, freq, flags);
> + if (IS_ERR(opp))
> + return PTR_ERR(opp);
> + dev_pm_opp_put(opp);
> +
> err = dev_pm_opp_set_rate(dev, *freq);
> if (err)
> return err;
>
> - *freq = clk_get_rate(pfdev->clock);
> -
> return 0;
> }
>
> @@ -60,20 +63,10 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
> return 0;
> }
>
> -static int panfrost_devfreq_get_cur_freq(struct device *dev, unsigned long *freq)
> -{
> - struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev));
> -
> - *freq = clk_get_rate(pfdev->clock);
> -
> - return 0;
> -}
> -
> static struct devfreq_dev_profile panfrost_devfreq_profile = {
> .polling_ms = 50, /* ~3 frames */
> .target = panfrost_devfreq_target,
> .get_dev_status = panfrost_devfreq_get_dev_status,
> - .get_cur_freq = panfrost_devfreq_get_cur_freq,
> };
>
> int panfrost_devfreq_init(struct panfrost_device *pfdev)
> --
> 2.20.1
>
On Mon, Nov 18, 2019 at 11:30 AM Steven Price <[email protected]> wrote:
>
> Currently when setting a frequency in panfrost_devfreq_target the
> returned frequency is the actual frequency that the clock driver reports
> (the return of clk_get_rate()). However, where the provided OPPs don't
> precisely match the frequencies that the clock actually achieves devfreq
> will then complain (repeatedly):
>
> devfreq devfreq0: Couldn't update frequency transition information.
>
> To avoid this change panfrost_devfreq_target() to fetch the opp using
> devfreq_recommened_opp() and not actually query the clock for the
> frequency.
>
> A similar problem exists with panfrost_devfreq_get_cur_freq(), but in
> this case because the function is optional we can just remove it and
> devfreq will fall back to using the previously set frequency.
>
> Fixes: 221bc77914cb ("drm/panfrost: Use generic code for devfreq")
> Signed-off-by: Steven Price <[email protected]>
> ---
> drivers/gpu/drm/panfrost/panfrost_devfreq.c | 19 ++++++-------------
> 1 file changed, 6 insertions(+), 13 deletions(-)
Applied.
Rob