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drm/panfrost: devfreq: Round frequencies to OPPs

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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 <steven.price@arm.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191118173002.32015-1-steven.price@arm.com
This commit is contained in:
Steven Price 2019-11-18 17:30:02 +00:00 committed by Rob Herring
parent 4adf0b49ee
commit 22bd4df9da
1 changed files with 6 additions and 13 deletions
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19
drivers/gpu/drm/panfrost/panfrost_devfreq.c
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@ -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)