From: Dmitry Osipenko digetx@gmail.com
commit 62bacb06b9f08965c4ef10e17875450490c948c0 upstream.
The kHz to Hz is incorrectly converted in a few places in the code, this results in a wrong frequency being calculated because devfreq core uses OPP frequencies that are given in Hz to clamp the rate, while tegra-devfreq gives to the core value in kHz and then it also expects to receive value in kHz from the core. In a result memory freq is always set to a value which is close to ULONG_MAX because of the bug. Hence the EMC frequency is always capped to the maximum and the driver doesn't do anything useful. This patch was tested on Tegra30 and Tegra124 SoC's, EMC frequency scaling works properly now.
Cc: stable@vger.kernel.org # 4.14+ Tested-by: Steev Klimaszewski steev@kali.org Reviewed-by: Chanwoo Choi cw00.choi@samsung.com Signed-off-by: Dmitry Osipenko digetx@gmail.com Acked-by: Thierry Reding treding@nvidia.com Signed-off-by: MyungJoo Ham myungjoo.ham@samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/devfreq/tegra-devfreq.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
--- a/drivers/devfreq/tegra-devfreq.c +++ b/drivers/devfreq/tegra-devfreq.c @@ -474,11 +474,11 @@ static int tegra_devfreq_target(struct d { struct tegra_devfreq *tegra = dev_get_drvdata(dev); struct dev_pm_opp *opp; - unsigned long rate = *freq * KHZ; + unsigned long rate;
- opp = devfreq_recommended_opp(dev, &rate, flags); + opp = devfreq_recommended_opp(dev, freq, flags); if (IS_ERR(opp)) { - dev_err(dev, "Failed to find opp for %lu KHz\n", *freq); + dev_err(dev, "Failed to find opp for %lu Hz\n", *freq); return PTR_ERR(opp); } rate = dev_pm_opp_get_freq(opp); @@ -487,8 +487,6 @@ static int tegra_devfreq_target(struct d clk_set_min_rate(tegra->emc_clock, rate); clk_set_rate(tegra->emc_clock, 0);
- *freq = rate; - return 0; }
@@ -498,7 +496,7 @@ static int tegra_devfreq_get_dev_status( struct tegra_devfreq *tegra = dev_get_drvdata(dev); struct tegra_devfreq_device *actmon_dev;
- stat->current_frequency = tegra->cur_freq; + stat->current_frequency = tegra->cur_freq * KHZ;
/* To be used by the tegra governor */ stat->private_data = tegra; @@ -553,7 +551,7 @@ static int tegra_governor_get_target(str target_freq = max(target_freq, dev->target_freq); }
- *freq = target_freq; + *freq = target_freq * KHZ;
return 0; }