[PATCH 05/23] interconnect: qcom: osm-l3: fix registration race

Johan Hovold
2023-02-01T10:16:56Z

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail:

of_icc_xlate_onecell: invalid index 0
cpu cpu0: error -EINVAL: error finding src node
cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 5bc9900addaf ("interconnect: qcom: Add OSM L3 interconnect provider support")
Cc: stable@vger.kernel.org # 5.7
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
drivers/interconnect/qcom/osm-l3.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
index 5fa171087425..3a1cbfe3e481 100644
--- a/drivers/interconnect/qcom/osm-l3.c
+++ b/drivers/interconnect/qcom/osm-l3.c
@@ -158,8 +158,8 @@ static int qcom_osm_l3_remove(struct platform_device *pdev)
{
struct qcom_osm_l3_icc_provider *qp = platform_get_drvdata(pdev);

+ icc_provider_deregister(&qp->provider);
icc_nodes_remove(&qp->provider);
- icc_provider_del(&qp->provider);

return 0;
}
@@ -245,14 +245,9 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
provider->set = qcom_osm_l3_set;
provider->aggregate = icc_std_aggregate;
provider->xlate = of_icc_xlate_onecell;
- INIT_LIST_HEAD(&provider->nodes);
provider->data = data;

- ret = icc_provider_add(provider);
- if (ret) {
- dev_err(&pdev->dev, "error adding interconnect provider\n");
- return ret;
- }
+ icc_provider_init(provider);

for (i = 0; i < num_nodes; i++) {
size_t j;
@@ -275,12 +270,15 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
}
data->num_nodes = num_nodes;

+ ret = icc_provider_register(provider);
+ if (ret)
+ goto err;
+
platform_set_drvdata(pdev, qp);

return 0;
err:
icc_nodes_remove(provider);
- icc_provider_del(provider);

return ret;
}
--
2.39.1