On Sat, Apr 19, 2025 at 09:30:58PM +0800, Hans Zhang wrote:
> If the call to pci_host_probe() in cdns_pcie_host_setup()
> fails, PM runtime count is decremented in the error path using
> pm_runtime_put_sync().But the runtime count is not incremented by this
> driver, but only by the callers (cdns_plat_pcie_probe/j721e_pcie_probe).
> And the callers also decrement theruntime PM count in their error path.
> So this leads to the below warning from the PM core:
>
> runtime PM usage count underflow!
>
> So fix it by getting rid of pm_runtime_put_sync() in the error path and
> directly return the errno.
>
> Fixes: 1b79c5284439 ("PCI: cadence: Add host driver for Cadence PCIe controller")
>
This is not the correct Fixes commit. In fact it took me a while to find the
correct one. This exact same issue was already fixed by commit, 19abcd790b51
("PCI: cadence: Fix cdns_pcie_{host|ep}_setup() error path").
But then, this bug got reintroduced while fixing the merge conflict in:
49e427e6bdd1 ("Merge branch 'pci/host-probe-refactor'")
I will change the tag while applying.
- Mani
> Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
> ---
> drivers/pci/controller/cadence/pcie-cadence-host.c | 11 +----------
> 1 file changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
> index 8af95e9da7ce..741e10a575ec 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-host.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
> @@ -570,14 +570,5 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
> if (!bridge->ops)
> bridge->ops = &cdns_pcie_host_ops;
>
> - ret = pci_host_probe(bridge);
> - if (ret < 0)
> - goto err_init;
> -
> - return 0;
> -
> - err_init:
> - pm_runtime_put_sync(dev);
> -
> - return ret;
> + return pci_host_probe(bridge);
> }
>
> base-commit: a24588245776dafc227243a01bfbeb8a59bafba9
> --
> 2.25.1
>
--
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