[PATCH] clk: qcom: gdsc: unwind power domains when registration fails

[Jesse Casco <jesse.casco@gmail.com>]

gdsc_register() leaves the power domains it has already initialized
registered with genpd when a later gdsc_init() or
of_genpd_add_provider_onecell() call fails. Callers only install their
gdsc_unregister() devm action after gdsc_register() returns success, so
nothing removes those domains, and a later probe attempt initializes
the same static struct generic_pm_domain objects again while they are
still on the genpd list.

Commit 86b23609d5e1 ("clk: qcom: gdsc: tear down per-domain genpds in
gdsc_unregister()") made the unregister path remove the domains, and
commit 16ba98dace9e ("clk: qcom: gdsc: Fix error path on registration
of multiple pm subdomains") fixed the subdomain part of the
registration error path. Make the rest of that error path match
gdsc_unregister(): when the provider cannot be added, remove all
subdomains and domains, and when gdsc_init() fails, remove the domains
initialized before it.

Fixes: 45dd0e55317c ("clk: qcom: Add support for GDSCs")
Signed-off-by: Jesse Casco <jesse.casco@gmail.com>
---
Tested in QEMU on a 7.3-rc5 tree, running the real gdsc.c and genpd
with a synthetic DT and fake registers, with failures injected at the
first, middle and last gdsc_init(), in subdomain registration and in
provider registration, plus sparse arrays, explicit parents, a device
parent and a pd_list (52 cases). 36 of the 52 cases failed the
cleanup checks before this patch; all 52 pass with it.

Registering the same objects again after a failed attempt still
reports an existing kobject (-EEXIST), with or without this patch;
that looks like a separate genpd lifecycle issue.

 drivers/clk/qcom/gdsc.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index be9c14e..8739293 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -647,7 +647,7 @@ int gdsc_register(struct gdsc_desc *desc,
 		scs[i]->rcdev = rcdev;
 		ret = gdsc_init(scs[i]);
 		if (ret)
-			return ret;
+			goto err_pm_domain_remove;
 		data->domains[i] = &scs[i]->pd;
 	}
 
@@ -666,10 +666,21 @@ int gdsc_register(struct gdsc_desc *desc,
 			goto err_pm_subdomain_remove;
 	}
 
-	return of_genpd_add_provider_onecell(dev->of_node, data);
+	ret = of_genpd_add_provider_onecell(dev->of_node, data);
+	if (ret)
+		goto err_pm_subdomain_remove;
+
+	return 0;
 
 err_pm_subdomain_remove:
 	gdsc_pm_subdomain_remove(desc, i);
+	i = num;
+
+err_pm_domain_remove:
+	while (i--) {
+		if (scs[i])
+			pm_genpd_remove(&scs[i]->pd);
+	}
 
 	return ret;
 }
-- 
2.56.0