[PATCH v2] soc: mediatek: Check if power domains can be powered on at boot time

From: Nicolas Boichat
Date: Sun Sep 27 2020 - 23:31:44 EST


In the error case, where a power domain cannot be powered on
successfully at boot time (in mtk_register_power_domains),
pm_genpd_init would still be called with is_off=false, and the
system would later try to disable the power domain again, triggering
warnings as disabled clocks are disabled again (and other potential
issues).

Also print a warning splat in that case, as this should never
happen.

Fixes: c84e358718a66f7 ("soc: Mediatek: Add SCPSYS power domain driver")
Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
---

Changes in v2:
- Add WARN_ON if the domain can't be powered on, to make it more
obvious that this should not happen (there is already an error
message).

drivers/soc/mediatek/mtk-scpsys.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index f669d3754627..ca75b14931ec 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -524,6 +524,7 @@ static void mtk_register_power_domains(struct platform_device *pdev,
for (i = 0; i < num; i++) {
struct scp_domain *scpd = &scp->domains[i];
struct generic_pm_domain *genpd = &scpd->genpd;
+ bool on;

/*
* Initially turn on all domains to make the domains usable
@@ -531,9 +532,9 @@ static void mtk_register_power_domains(struct platform_device *pdev,
* software. The unused domains will be switched off during
* late_init time.
*/
- genpd->power_on(genpd);
+ on = !WARN_ON(genpd->power_on(genpd) < 0);

- pm_genpd_init(genpd, NULL, false);
+ pm_genpd_init(genpd, NULL, !on);
}

/*
--
2.28.0.681.g6f77f65b4e-goog