The memory activity counter may get a bit higher than a watermark which is selected based on OPP that corresponds to a highest EMC rate, in this case watermark is lower than the actual memory activity is and thus results in unwanted "upper" interrupts.
Signed-off-by: Dmitry Osipenko <dig...@gmail.com> --- drivers/devfreq/tegra30-devfreq.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c index 8d6bf6e9f1ae..c3cf87231d25 100644 --- a/drivers/devfreq/tegra30-devfreq.c +++ b/drivers/devfreq/tegra30-devfreq.c @@ -363,7 +363,18 @@ static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra, tegra_actmon_get_lower_upper(tegra, dev, freq - 1, &lower, &upper); delta = do_percent(upper - lower, dev->config->boost_up_threshold); - device_writel(dev, lower + delta, ACTMON_DEV_UPPER_WMARK); + + /* + * The memory events count could go a bit higher than the maximum + * defined by the OPPs, hence make the upper watermark infinitely + * high to avoid unnecessary upper interrupts in that case. + */ + if (freq == tegra->max_freq) + upper = ULONG_MAX; + else + upper = lower + delta; + + device_writel(dev, upper, ACTMON_DEV_UPPER_WMARK); /* * Meanwhile the lower mark is based on the average value -- 2.22.0