[PATCH 5.4 231/344] perf/imx_ddr: Fix cpu hotplug state cleanup

Greg Kroah-Hartman
2020-02-21T08:33:14Z

From: Leonard Crestez <leonard.crestez@nxp.com>

[ Upstream commit 9ee68b314e9aa63ed11b98beb8a68810b8234dcf ]

This driver allocates a dynamic cpu hotplug state but never releases it.
If reloaded in a loop it will quickly trigger a WARN message:

"No more dynamic states available for CPU hotplug"

Fix by calling cpuhp_remove_multi_state on remove like several other
perf pmu drivers.

Also fix the cleanup logic on probe error paths: add the missing
cpuhp_remove_multi_state call and properly check the return value from
cpuhp_state_add_instant_nocalls.

Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf")
Acked-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/perf/fsl_imx8_ddr_perf.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index 2a3966d059e70..0e51baa48b149 100644
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -572,13 +572,17 @@ static int ddr_perf_probe(struct platform_device *pdev)

if (ret < 0) {
dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
- goto ddr_perf_err;
+ goto cpuhp_state_err;
}

pmu->cpuhp_state = ret;

/* Register the pmu instance for cpu hotplug */
- cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+ ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+ if (ret) {
+ dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
+ goto cpuhp_instance_err;
+ }

/* Request irq */
irq = of_irq_get(np, 0);
@@ -612,9 +616,10 @@ static int ddr_perf_probe(struct platform_device *pdev)
return 0;

ddr_perf_err:
- if (pmu->cpuhp_state)
- cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
-
+ cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+cpuhp_instance_err:
+ cpuhp_remove_multi_state(pmu->cpuhp_state);
+cpuhp_state_err:
ida_simple_remove(&ddr_ida, pmu->id);
dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
return ret;
@@ -625,6 +630,7 @@ static int ddr_perf_remove(struct platform_device *pdev)
struct ddr_pmu *pmu = platform_get_drvdata(pdev);

cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+ cpuhp_remove_multi_state(pmu->cpuhp_state);
irq_set_affinity_hint(pmu->irq, NULL);

perf_pmu_unregister(&pmu->pmu);
--
2.20.1