Re: [PATCH v9 07/17] PM / devfreq: tegra30: Support interconnect and OPPs from device-tree

[Viresh Kumar]

On 17-11-20, 17:17, Dmitry Osipenko wrote:
> 17.11.2020 13:07, Viresh Kumar пишет:
> > On 16-11-20, 00:29, Dmitry Osipenko wrote:
> >> This patch moves ACTMON driver away from generating OPP table by itself,
> >> transitioning it to use the table which comes from device-tree. This
> >> change breaks compatibility with older device-trees in order to bring
> >> support for the interconnect framework to the driver. This is a mandatory
> >> change which needs to be done in order to implement interconnect-based
> >> memory DVFS. Users of legacy device-trees will get a message telling that
> >> theirs DT needs to be upgraded. Now ACTMON issues memory bandwidth request
> >> using dev_pm_opp_set_bw(), instead of driving EMC clock rate directly.
> >>
> >> Tested-by: Peter Geis <pgwipeout@xxxxxxxxx>
> >> Tested-by: Nicolas Chauvet <kwizart@xxxxxxxxx>
> >> Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> >> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> >> ---
> >>  drivers/devfreq/tegra30-devfreq.c | 86 ++++++++++++++++---------------
> >>  1 file changed, 44 insertions(+), 42 deletions(-)
> >>
> >> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> >> index 38cc0d014738..ed6d4469c8c7 100644
> >> --- a/drivers/devfreq/tegra30-devfreq.c
> >> +++ b/drivers/devfreq/tegra30-devfreq.c
> >> @@ -19,6 +19,8 @@
> >>  #include <linux/reset.h>
> >>  #include <linux/workqueue.h>
> >>  
> >> +#include <soc/tegra/fuse.h>
> >> +
> >>  #include "governor.h"
> >>  
> >>  #define ACTMON_GLB_STATUS					0x0
> >> @@ -155,6 +157,7 @@ struct tegra_devfreq_device {
> >>  
> >>  struct tegra_devfreq {
> >>  	struct devfreq		*devfreq;
> >> +	struct opp_table	*opp_table;
> >>  
> >>  	struct reset_control	*reset;
> >>  	struct clk		*clock;
> >> @@ -612,34 +615,19 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
> >>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
> >>  				u32 flags)
> >>  {
> >> -	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
> >> -	struct devfreq *devfreq = tegra->devfreq;
> >>  	struct dev_pm_opp *opp;
> >> -	unsigned long rate;
> >> -	int err;
> >> +	int ret;
> >>  
> >>  	opp = devfreq_recommended_opp(dev, freq, flags);
> >>  	if (IS_ERR(opp)) {
> >>  		dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
> >>  		return PTR_ERR(opp);
> >>  	}
> >> -	rate = dev_pm_opp_get_freq(opp);
> >> -	dev_pm_opp_put(opp);
> >> -
> >> -	err = clk_set_min_rate(tegra->emc_clock, rate * KHZ);
> >> -	if (err)
> >> -		return err;
> >> -
> >> -	err = clk_set_rate(tegra->emc_clock, 0);
> >> -	if (err)
> >> -		goto restore_min_rate;
> >>  
> >> -	return 0;
> >> -
> >> -restore_min_rate:
> >> -	clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
> >> +	ret = dev_pm_opp_set_bw(dev, opp);
> >> +	dev_pm_opp_put(opp);
> >>  
> >> -	return err;
> >> +	return ret;
> >>  }
> >>  
> >>  static int tegra_devfreq_get_dev_status(struct device *dev,
> >> @@ -655,7 +643,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev,
> >>  	stat->private_data = tegra;
> >>  
> >>  	/* The below are to be used by the other governors */
> >> -	stat->current_frequency = cur_freq;
> >> +	stat->current_frequency = cur_freq * KHZ;
> >>  
> >>  	actmon_dev = &tegra->devices[MCALL];
> >>  
> >> @@ -705,7 +693,12 @@ static int tegra_governor_get_target(struct devfreq *devfreq,
> >>  		target_freq = max(target_freq, dev->target_freq);
> >>  	}
> >>  
> >> -	*freq = target_freq;
> >> +	/*
> >> +	 * tegra-devfreq driver operates with KHz units, while OPP table
> >> +	 * entries use Hz units. Hence we need to convert the units for the
> >> +	 * devfreq core.
> >> +	 */
> >> +	*freq = target_freq * KHZ;
> >>  
> >>  	return 0;
> >>  }
> >> @@ -774,6 +767,7 @@ static struct devfreq_governor tegra_devfreq_governor = {
> >>  
> >>  static int tegra_devfreq_probe(struct platform_device *pdev)
> >>  {
> >> +	u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
> >>  	struct tegra_devfreq_device *dev;
> >>  	struct tegra_devfreq *tegra;
> >>  	struct devfreq *devfreq;
> >> @@ -781,6 +775,13 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> >>  	long rate;
> >>  	int err;
> >>  
> >> +	/* legacy device-trees don't have OPP table and must be updated */
> >> +	if (!device_property_present(&pdev->dev, "operating-points-v2")) {
> >> +		dev_err(&pdev->dev,
> >> +			"OPP table not found, please update your device tree\n");
> >> +		return -ENODEV;
> >> +	}
> >> +
> > 
> > You forgot to remove this ?
> 
> Yes, good catch. I'm planning to replace this code with a common helper
> sometime soon, so if there won't be another reasons to make a new
> revision, then I'd prefer to keep it as-is for now.

You should just replace this patch only with a version of V9.1 and you
aren't really required to resend the whole series. And you should fix
it before it gets merged. This isn't a formatting issue which we just
let through. I trust you when you say that you will fix it, but this
must be fixed now.

-- 
viresh