[PATCH] bus: mhi: pci_generic: Fix erroneous system suspend abort

[Len Brown <lenb@kernel.org>]

From: Len Brown <len.brown@intel.com>

mhi sometimes aborts system suspend on the thinkpad T16 gen3:

mhi-pci-generic 0000:08:00.0: failed to suspend device: -16
mhi-pci-generic 0000:08:00.0: PM: pci_pm_suspend(): mhi_pci_suspend [mhi_pci_generic] returns -16
mhi-pci-generic 0000:08:00.0: PM: dpm_run_callback(): pci_pm_suspend returns -16
mhi-pci-generic 0000:08:00.0: PM: pci_pm_suspend returned -16 after 15145 usecs
mhi-pci-generic 0000:08:00.0: PM: failed to suspend async: error -16

When a driver returns -EBUSY for its runtime suspend method,
that means "try again later".

But when a driver returns anything but 0 from its system-suspend
method, that means "abort system suspend".

Always return 0 from mhi_pci_suspend().

Fixes: d3800c1dce24 ("bus: mhi: pci_generic: Add support for runtime PM")
Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/bus/mhi/host/pci_generic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 7193a384cca4..b036fa6e06c4 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -1727,7 +1727,8 @@ static int __maybe_unused mhi_pci_runtime_resume(struct device *dev)
 static int  __maybe_unused mhi_pci_suspend(struct device *dev)
 {
 	pm_runtime_disable(dev);
-	return mhi_pci_runtime_suspend(dev);
+	mhi_pci_runtime_suspend(dev);
+	return 0;
 }
 
 static int __maybe_unused mhi_pci_resume(struct device *dev)
-- 
2.45.2