| Message ID | 20210721224056.3035016-1-bjorn.andersson@linaro.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | [v2] clk: qcom: gdsc: Ensure regulator init state matches GDSC state | expand |
Quoting Bjorn Andersson (2021-07-21 15:40:56) > As GDSCs are registered and found to be already enabled gdsc_init() > ensures that 1) the kernel state matches the hardware state, and 2) > votable GDSCs are properly enabled from this master as well. > > But as the (optional) supply regulator is enabled deep into > gdsc_toggle_logic(), which is only executed for votable GDSCs the > kernel's state of the regulator might not match the hardware. The > regulator might be automatically turned off if no other users are > present or the next call to gdsc_disable() would cause an unbalanced > regulator_disable(). > > But as the votable case deals with an already enabled GDSC, most of > gdsc_enable() and gdsc_toggle_logic() can be skipped. Reducing it to > just clearing the SW_COLLAPSE_MASK and enabling hardware control allow > us to simply call regulator_enable() in both cases. > > The enablement of hardware control seems to be an independent property > from the GDSC being enabled, so this is moved outside that conditional > segment. > > Lastly, as the propagation of ALWAY_ON to GENPD_FLAG_ALWAYS_ON needs to > happen regardless of the initial state this is grouped together with the > other sc->pd updates at the end of the function. > > Cc: stable@vger.kernel.org > Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- I was hoping someone from qcom would review it. I'll take a look in the next couple of days and probably throw it on clk-fixes for the next rc. -Stephen > > Changes since v1: > - Refactored into if (on) else if (ALWAYS_ON) style > - Extracted relevant parts of gdsc_enable() to call under VOTABLE > - Turn on hwctrl if requested for non-votable gdscs > > drivers/clk/qcom/gdsc.c | 54 +++++++++++++++++++++++++++-------------- > 1 file changed, 36 insertions(+), 18 deletions(-) > > diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c > index 51ed640e527b..4ece326ea233 100644 > --- a/drivers/clk/qcom/gdsc.c > +++ b/drivers/clk/qcom/gdsc.c > @@ -357,27 +357,43 @@ static int gdsc_init(struct gdsc *sc) > if (on < 0) > return on; > > - /* > - * Votable GDSCs can be ON due to Vote from other masters. > - * If a Votable GDSC is ON, make sure we have a Vote. > - */ > - if ((sc->flags & VOTABLE) && on) > - gdsc_enable(&sc->pd); > + if (on) { > + /* The regulator must be on, sync the kernel state */ > + if (sc->rsupply) { > + ret = regulator_enable(sc->rsupply); > + if (ret < 0) > + return ret; > + } > > - /* > - * Make sure the retain bit is set if the GDSC is already on, otherwise > - * we end up turning off the GDSC and destroying all the register > - * contents that we thought we were saving. > - */ > - if ((sc->flags & RETAIN_FF_ENABLE) && on) > - gdsc_retain_ff_on(sc); > + /* > + * Votable GDSCs can be ON due to Vote from other masters. > + * If a Votable GDSC is ON, make sure we have a Vote. > + */ > + if (sc->flags & VOTABLE) { > + ret = regmap_update_bits(sc->regmap, sc->gdscr, > + SW_COLLAPSE_MASK, val); > + if (ret) > + return ret; > + } > + > + /* Turn on HW trigger mode if supported */ > + if (sc->flags & HW_CTRL) { > + ret = gdsc_hwctrl(sc, true); > + if (ret < 0) > + return ret; > + } > > - /* If ALWAYS_ON GDSCs are not ON, turn them ON */ > - if (sc->flags & ALWAYS_ON) { > - if (!on) > - gdsc_enable(&sc->pd); > + /* > + * Make sure the retain bit is set if the GDSC is already on, > + * otherwise we end up turning off the GDSC and destroying all > + * the register contents that we thought we were saving. > + */ > + if (sc->flags & RETAIN_FF_ENABLE) > + gdsc_retain_ff_on(sc); > + } else if (sc->flags & ALWAYS_ON) { > + /* If ALWAYS_ON GDSCs are not ON, turn them ON */ > + gdsc_enable(&sc->pd); > on = true; > - sc->pd.flags |= GENPD_FLAG_ALWAYS_ON; > } > > if (on || (sc->pwrsts & PWRSTS_RET)) > @@ -385,6 +401,8 @@ static int gdsc_init(struct gdsc *sc) > else > gdsc_clear_mem_on(sc); > > + if (sc->flags & ALWAYS_ON) > + sc->pd.flags |= GENPD_FLAG_ALWAYS_ON; > if (!sc->pd.power_off) > sc->pd.power_off = gdsc_disable; > if (!sc->pd.power_on) > -- > 2.29.2 >
Quoting Bjorn Andersson (2021-07-21 15:40:56) > As GDSCs are registered and found to be already enabled gdsc_init() > ensures that 1) the kernel state matches the hardware state, and 2) > votable GDSCs are properly enabled from this master as well. > > But as the (optional) supply regulator is enabled deep into > gdsc_toggle_logic(), which is only executed for votable GDSCs the > kernel's state of the regulator might not match the hardware. The > regulator might be automatically turned off if no other users are > present or the next call to gdsc_disable() would cause an unbalanced > regulator_disable(). > > But as the votable case deals with an already enabled GDSC, most of > gdsc_enable() and gdsc_toggle_logic() can be skipped. Reducing it to > just clearing the SW_COLLAPSE_MASK and enabling hardware control allow > us to simply call regulator_enable() in both cases. > > The enablement of hardware control seems to be an independent property > from the GDSC being enabled, so this is moved outside that conditional > segment. > > Lastly, as the propagation of ALWAY_ON to GENPD_FLAG_ALWAYS_ON needs to > happen regardless of the initial state this is grouped together with the > other sc->pd updates at the end of the function. > > Cc: stable@vger.kernel.org > Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- Applied to clk-fixes
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 51ed640e527b..4ece326ea233 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -357,27 +357,43 @@ static int gdsc_init(struct gdsc *sc) if (on < 0) return on; - /* - * Votable GDSCs can be ON due to Vote from other masters. - * If a Votable GDSC is ON, make sure we have a Vote. - */ - if ((sc->flags & VOTABLE) && on) - gdsc_enable(&sc->pd); + if (on) { + /* The regulator must be on, sync the kernel state */ + if (sc->rsupply) { + ret = regulator_enable(sc->rsupply); + if (ret < 0) + return ret; + } - /* - * Make sure the retain bit is set if the GDSC is already on, otherwise - * we end up turning off the GDSC and destroying all the register - * contents that we thought we were saving. - */ - if ((sc->flags & RETAIN_FF_ENABLE) && on) - gdsc_retain_ff_on(sc); + /* + * Votable GDSCs can be ON due to Vote from other masters. + * If a Votable GDSC is ON, make sure we have a Vote. + */ + if (sc->flags & VOTABLE) { + ret = regmap_update_bits(sc->regmap, sc->gdscr, + SW_COLLAPSE_MASK, val); + if (ret) + return ret; + } + + /* Turn on HW trigger mode if supported */ + if (sc->flags & HW_CTRL) { + ret = gdsc_hwctrl(sc, true); + if (ret < 0) + return ret; + } - /* If ALWAYS_ON GDSCs are not ON, turn them ON */ - if (sc->flags & ALWAYS_ON) { - if (!on) - gdsc_enable(&sc->pd); + /* + * Make sure the retain bit is set if the GDSC is already on, + * otherwise we end up turning off the GDSC and destroying all + * the register contents that we thought we were saving. + */ + if (sc->flags & RETAIN_FF_ENABLE) + gdsc_retain_ff_on(sc); + } else if (sc->flags & ALWAYS_ON) { + /* If ALWAYS_ON GDSCs are not ON, turn them ON */ + gdsc_enable(&sc->pd); on = true; - sc->pd.flags |= GENPD_FLAG_ALWAYS_ON; } if (on || (sc->pwrsts & PWRSTS_RET)) @@ -385,6 +401,8 @@ static int gdsc_init(struct gdsc *sc) else gdsc_clear_mem_on(sc); + if (sc->flags & ALWAYS_ON) + sc->pd.flags |= GENPD_FLAG_ALWAYS_ON; if (!sc->pd.power_off) sc->pd.power_off = gdsc_disable; if (!sc->pd.power_on)
As GDSCs are registered and found to be already enabled gdsc_init() ensures that 1) the kernel state matches the hardware state, and 2) votable GDSCs are properly enabled from this master as well. But as the (optional) supply regulator is enabled deep into gdsc_toggle_logic(), which is only executed for votable GDSCs the kernel's state of the regulator might not match the hardware. The regulator might be automatically turned off if no other users are present or the next call to gdsc_disable() would cause an unbalanced regulator_disable(). But as the votable case deals with an already enabled GDSC, most of gdsc_enable() and gdsc_toggle_logic() can be skipped. Reducing it to just clearing the SW_COLLAPSE_MASK and enabling hardware control allow us to simply call regulator_enable() in both cases. The enablement of hardware control seems to be an independent property from the GDSC being enabled, so this is moved outside that conditional segment. Lastly, as the propagation of ALWAY_ON to GENPD_FLAG_ALWAYS_ON needs to happen regardless of the initial state this is grouped together with the other sc->pd updates at the end of the function. Cc: stable@vger.kernel.org Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- Changes since v1: - Refactored into if (on) else if (ALWAYS_ON) style - Extracted relevant parts of gdsc_enable() to call under VOTABLE - Turn on hwctrl if requested for non-votable gdscs drivers/clk/qcom/gdsc.c | 54 +++++++++++++++++++++++++++-------------- 1 file changed, 36 insertions(+), 18 deletions(-)