[PATCH 2/5] clk: imx95-blk-ctl: Fix synchronous abort

Peng Fan
2025-07-01T07:38:40Z

From: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>

When enabling runtime PM for clock suppliers that also belong to a power
domain, the following crash is thrown:

---
Internal error: synchronous external abort: 0000000096000010 [#1] PREEMPT SMP
Workqueue: events_unbound deferred_probe_work_func
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : clk_mux_get_parent+0x60/0x90
lr : clk_core_reparent_orphans_nolock+0x58/0xd8
Call trace:
clk_mux_get_parent+0x60/0x90
clk_core_reparent_orphans_nolock+0x58/0xd8
of_clk_add_hw_provider.part.0+0x90/0x100
of_clk_add_hw_provider+0x1c/0x38
imx95_bc_probe+0x2e0/0x3f0
platform_probe+0x70/0xd8

Enabling runtime PM without explicitly resuming the device caused
the power domain cut off after clk_register() is called. As a result,
a crash happens when the clock hardware provider is added and attempts
to access the BLK_CTL register

Fix this by using devm_pm_runtime_enable() instead of pm_runtime_enable()
and getting rid of the pm_runtime_disable() in the cleanup path.

Fixes: 5224b189462f ("clk: imx: add i.MX95 BLK CTL clk driver")
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
drivers/clk/imx/clk-imx95-blk-ctl.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
index cc2ee2be18195f0e05e911bcb26e284b1a894244..86bdcd21753102b7d160288e7b69bf73da5a5706 100644
--- a/drivers/clk/imx/clk-imx95-blk-ctl.c
+++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
@@ -342,8 +342,10 @@ static int imx95_bc_probe(struct platform_device *pdev)
if (!clk_hw_data)
return -ENOMEM;

- if (bc_data->rpm_enabled)
- pm_runtime_enable(&pdev->dev);
+ if (bc_data->rpm_enabled) {
+ devm_pm_runtime_enable(&pdev->dev);
+ pm_runtime_resume_and_get(&pdev->dev);
+ }

clk_hw_data->num = bc_data->num_clks;
hws = clk_hw_data->hws;
@@ -383,8 +385,10 @@ static int imx95_bc_probe(struct platform_device *pdev)
goto cleanup;
}

- if (pm_runtime_enabled(bc->dev))
+ if (pm_runtime_enabled(bc->dev)) {
+ pm_runtime_put_sync(&pdev->dev);
clk_disable_unprepare(bc->clk_apb);
+ }

return 0;

@@ -395,9 +399,6 @@ static int imx95_bc_probe(struct platform_device *pdev)
clk_hw_unregister(hws[i]);
}

- if (bc_data->rpm_enabled)
- pm_runtime_disable(&pdev->dev);
-
return ret;
}

--
2.37.1