This is a note to let you know that I've just added the patch titled
pmdomain: mediatek: fix race conditions with genpd
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pmdomain-mediatek-fix-race-conditions-with-genpd.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b5a0d374739adce526350da6980e8c1a9d0cc87f
Author: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
Date: Mon Dec 25 15:36:15 2023 +0200
pmdomain: mediatek: fix race conditions with genpd
[ Upstream commit c41336f4d69057cbf88fed47951379b384540df5 ]
If the power domains are registered first with genpd and *after that*
the driver attempts to power them on in the probe sequence, then it is
possible that a race condition occurs if genpd tries to power them on
in the same time.
The same is valid for powering them off before unregistering them
from genpd.
Attempt to fix race conditions by first removing the domains from genpd
and *after that* powering down domains.
Also first power up the domains and *after that* register them
to genpd.
Fixes: 59b644b01cf4 ("soc: mediatek: Add MediaTek SCPSYS power domains")
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20231225133615.78993-1-eugen.hristev@xxxxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
index 52ecde8e446cf..9e649b7077c6a 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -493,6 +493,11 @@ static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *paren
goto err_put_node;
}
+ /* recursive call to add all subdomains */
+ ret = scpsys_add_subdomain(scpsys, child);
+ if (ret)
+ goto err_put_node;
+
ret = pm_genpd_add_subdomain(parent_pd, child_pd);
if (ret) {
dev_err(scpsys->dev, "failed to add %s subdomain to parent %s\n",
@@ -502,11 +507,6 @@ static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *paren
dev_dbg(scpsys->dev, "%s add subdomain: %s\n", parent_pd->name,
child_pd->name);
}
-
- /* recursive call to add all subdomains */
- ret = scpsys_add_subdomain(scpsys, child);
- if (ret)
- goto err_put_node;
}
return 0;
@@ -520,9 +520,6 @@ static void scpsys_remove_one_domain(struct scpsys_domain *pd)
{
int ret;
- if (scpsys_domain_is_on(pd))
- scpsys_power_off(&pd->genpd);
-
/*
* We're in the error cleanup already, so we only complain,
* but won't emit another error on top of the original one.
@@ -532,6 +529,8 @@ static void scpsys_remove_one_domain(struct scpsys_domain *pd)
dev_err(pd->scpsys->dev,
"failed to remove domain '%s' : %d - state may be inconsistent\n",
pd->genpd.name, ret);
+ if (scpsys_domain_is_on(pd))
+ scpsys_power_off(&pd->genpd);
clk_bulk_put(pd->num_clks, pd->clks);
clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
