As GDSCs are registered and found to be already enabled gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that the vote is matching the hardware state. Part of this the related regulator will be enabled.
But for non-votable GDSCs the regulator and GDSC status will be out of sync and as the GDSC is later disabled regulator_disable() will face an unbalanced enable-count, or something might turn off the supply under the feet of the GDSC.
So ensure that the regulator is enabled even for non-votable GDSCs.
Cc: stable@vger.kernel.org Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org --- drivers/clk/qcom/gdsc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 51ed640e527b..f7e7759cdb90 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -359,10 +359,17 @@ static int gdsc_init(struct gdsc *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 a Votable GDSC is ON, make sure we have a Vote. If + * non-votable, ensure that the supply is kept enabled (as + * is done by gdsc_enable). */ - if ((sc->flags & VOTABLE) && on) + if ((sc->flags & VOTABLE) && on) { gdsc_enable(&sc->pd); + } else if (on) { + ret = regulator_enable(sc->rsupply); + if (ret < 0) + return ret; + }
/* * Make sure the retain bit is set if the GDSC is already on, otherwise
On 25-06-21, 15:54, Bjorn Andersson wrote:
As GDSCs are registered and found to be already enabled gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that the vote is matching the hardware state. Part of this the related regulator will be enabled.
But for non-votable GDSCs the regulator and GDSC status will be out of sync and as the GDSC is later disabled regulator_disable() will face an unbalanced enable-count, or something might turn off the supply under the feet of the GDSC.
So ensure that the regulator is enabled even for non-votable GDSCs.
Reviewed-by: Vinod Koul vkoul@kernel.org
Quoting Bjorn Andersson (2021-06-25 15:54:14)
As GDSCs are registered and found to be already enabled gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that the vote is matching the hardware state. Part of this the related regulator will be enabled.
But for non-votable GDSCs the regulator and GDSC status will be out of sync and as the GDSC is later disabled regulator_disable() will face an unbalanced enable-count, or something might turn off the supply under the feet of the GDSC.
So ensure that the regulator is enabled even for non-votable GDSCs.
Cc: stable@vger.kernel.org Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
drivers/clk/qcom/gdsc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 51ed640e527b..f7e7759cdb90 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -359,10 +359,17 @@ static int gdsc_init(struct gdsc *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 a Votable GDSC is ON, make sure we have a Vote. If* non-votable, ensure that the supply is kept enabled (as* is done by gdsc_enable). */
if ((sc->flags & VOTABLE) && on)
if ((sc->flags & VOTABLE) && on) { gdsc_enable(&sc->pd);} else if (on) {ret = regulator_enable(sc->rsupply);if (ret < 0)return ret;
Looking at this makes me think we've messed something up with gdsc_enable() being called or cherry-picking the regulator enable (and other stuff in this gdsc_init()) out of the enable path. Maybe we should have a followup patch that replaces the gdsc_enable() with gdsc_toggle_logic(sc, GDSC_ON) so that we know it isn't doing anything else during init like asserting a reset when presumably all we want to do is toggle the enable bit to assert our vote.
And I notice that we already call gdsc_toggle_logic() in gdsc_init(), so then we'll have a double regulator_enable() in the case of PWRSTS_ON? And then if the flag is ALWAYS_ON we'll call regulator_enable() yet again, but luckily only if it isn't on initially, phew! This code is quite twisted.
It would be super nice to make it more like
if (on) { /* It was on in hardware, sync kernel state */ regulator_enable();
if (votable) write bit, why do any wait?
if (retain ff) write bit } else if (always_on) { /* Force on */ gdsc_enable(); on = true; }
if (on || ...)
}/* * Make sure the retain bit is set if the GDSC is already on, otherwise
On Tue 29 Jun 01:34 CDT 2021, Stephen Boyd wrote:
Quoting Bjorn Andersson (2021-06-25 15:54:14)
As GDSCs are registered and found to be already enabled gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that the vote is matching the hardware state. Part of this the related regulator will be enabled.
But for non-votable GDSCs the regulator and GDSC status will be out of sync and as the GDSC is later disabled regulator_disable() will face an unbalanced enable-count, or something might turn off the supply under the feet of the GDSC.
So ensure that the regulator is enabled even for non-votable GDSCs.
Cc: stable@vger.kernel.org Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
drivers/clk/qcom/gdsc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 51ed640e527b..f7e7759cdb90 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -359,10 +359,17 @@ static int gdsc_init(struct gdsc *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 a Votable GDSC is ON, make sure we have a Vote. If* non-votable, ensure that the supply is kept enabled (as* is done by gdsc_enable). */
if ((sc->flags & VOTABLE) && on)
if ((sc->flags & VOTABLE) && on) { gdsc_enable(&sc->pd);} else if (on) {ret = regulator_enable(sc->rsupply);if (ret < 0)return ret;Looking at this makes me think we've messed something up with gdsc_enable() being called or cherry-picking the regulator enable (and other stuff in this gdsc_init()) out of the enable path. Maybe we should have a followup patch that replaces the gdsc_enable() with gdsc_toggle_logic(sc, GDSC_ON) so that we know it isn't doing anything else during init like asserting a reset when presumably all we want to do is toggle the enable bit to assert our vote.
And I notice that we already call gdsc_toggle_logic() in gdsc_init(), so then we'll have a double regulator_enable() in the case of PWRSTS_ON? And then if the flag is ALWAYS_ON we'll call regulator_enable() yet again, but luckily only if it isn't on initially, phew! This code is quite twisted.
It would be super nice to make it more like
if (on) { /* It was on in hardware, sync kernel state */ regulator_enable();
if (votable) write bit, why do any wait? if (retain ff) write bit} else if (always_on) { /* Force on */ gdsc_enable(); on = true; }
if (on || ...)
This does look cleaner, I will dig through the logic here once more before figuring out what to do for v2.
Thanks, Bjorn
}/* * Make sure the retain bit is set if the GDSC is already on, otherwise
On Fri 25 Jun 17:54 CDT 2021, Bjorn Andersson wrote:
As GDSCs are registered and found to be already enabled gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that the vote is matching the hardware state. Part of this the related regulator will be enabled.
But for non-votable GDSCs the regulator and GDSC status will be out of sync and as the GDSC is later disabled regulator_disable() will face an unbalanced enable-count, or something might turn off the supply under the feet of the GDSC.
So ensure that the regulator is enabled even for non-votable GDSCs.
Cc: stable@vger.kernel.org Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies") Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
drivers/clk/qcom/gdsc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 51ed640e527b..f7e7759cdb90 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -359,10 +359,17 @@ static int gdsc_init(struct gdsc *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 a Votable GDSC is ON, make sure we have a Vote. If* non-votable, ensure that the supply is kept enabled (as* is done by gdsc_enable).
- if ((sc->flags & VOTABLE) && on)
- if ((sc->flags & VOTABLE) && on) { gdsc_enable(&sc->pd);
- } else if (on) {
I somehow lost the check for sc->rsupply != NULL while trying to make this readable. In other words, this is broken.
Regards, Bjorn
ret = regulator_enable(sc->rsupply);if (ret < 0)return ret;- }
/* * Make sure the retain bit is set if the GDSC is already on, otherwise -- 2.29.2
linux-stable-mirror@lists.linaro.org
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Bjorn Andersson -
Stephen Boyd -
Vinod Koul