[PATCH v1 4/4] clk: scpi: register scpi-cpufreq once and clear on failure

[Xixin Liu]

scpi_clk_probe() walks clock children and, for each DVFS provider, calls
platform_device_register_simple("scpi-cpufreq"). Two related bugs:

1) Multiple DVFS children each spawned another virtual cpufreq device.
   If cpufreq_dev is already set, continue and skip a second register.

2) On IS_ERR, the pointer still held ERR_PTR (e.g. -ENOMEM). remove()
   treats any non-NULL cpufreq_dev as live and would call
   platform_device_unregister() on the error pointer (oops). Clear
   cpufreq_dev to NULL after the failure warn so remove() skips it.

Signed-off-by: Xixin Liu <liuxixin@xxxxxxxxxx>
---
 drivers/clk/clk-scpi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-scpi.c b/drivers/clk/clk-scpi.c
index 4e22ba12b157..ce6baea8f82e 100644
--- a/drivers/clk/clk-scpi.c
+++ b/drivers/clk/clk-scpi.c
@@ -283,10 +283,14 @@ static int scpi_clocks_probe(struct platform_device *pdev)
 		if (match->data != &scpi_dvfs_ops)
 			continue;
 		/* Add the virtual cpufreq device if it's DVFS clock provider */
+		if (cpufreq_dev)
+			continue;
 		cpufreq_dev = platform_device_register_simple("scpi-cpufreq",
 							      -1, NULL, 0);
-		if (IS_ERR(cpufreq_dev))
+		if (IS_ERR(cpufreq_dev)) {
 			pr_warn("unable to register cpufreq device");
+			cpufreq_dev = NULL;
+		}
 	}
 	return 0;
 }
-- 
2.53.0