Re: [PATCH v6 51/52] PM / devfreq: tegra30: Support interconnect and OPPs from device-tree

[Chanwoo Choi]

Hi Dmitry,

On Mon, Nov 2, 2020 at 12:24 AM Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>
> 01.11.2020 17:44, Chanwoo Choi пишет:
> > Hi Dmitry,
> >
> > On Mon, Oct 26, 2020 at 7:22 AM Dmitry Osipenko <digetx@xxxxxxxxx> 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>
> >> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> >> ---
> >>  drivers/devfreq/tegra30-devfreq.c | 91 ++++++++++++++++---------------
> >>  1 file changed, 48 insertions(+), 43 deletions(-)
> >>
> >> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> >> index 3f732ab53573..1b0b91a71886 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>
> >> +
> >
> > This patch touches the OPP. Is it related to this change?
>
> Yes, this is needed for the dev_pm_opp_set_supported_hw().

OK.

>
> >>  #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);
> >> +               dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
> >
> > You used the 'Failed to' format in almost every error case.
> > Don't need to change it.
> > (snip)
>
> Good catch, thanks.



-- 
Best Regards,
Chanwoo Choi