[RFC 2/2] bus: mhi: host: Add diagnostic print for -EBUSY in mhi_pm_suspend()

[Len Brown <lenb@kernel.org>]

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

mhi_pm_suspend() sometimes returns -EBUSY, but doesn't tell us why.

Print dev_wake and pending_pkts when it does.

Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/bus/mhi/host/pm.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index ced83fbb1a51..2eb7344b3b39 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -871,8 +871,12 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 
 	/* Return busy if there are any pending resources */
 	if (atomic_read(&mhi_cntrl->dev_wake) ||
-	    atomic_read(&mhi_cntrl->pending_pkts))
+	    atomic_read(&mhi_cntrl->pending_pkts)) {
+		dev_err(dev, "DEBUG: suspend busy (early): dev_wake: %d pending_pkts: %d\n",
+			atomic_read(&mhi_cntrl->dev_wake),
+			atomic_read(&mhi_cntrl->pending_pkts));
 		return -EBUSY;
+	}
 
 	/* Take MHI out of M2 state */
 	read_lock_bh(&mhi_cntrl->pm_lock);
@@ -900,6 +904,9 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 	if (atomic_read(&mhi_cntrl->dev_wake) ||
 	    atomic_read(&mhi_cntrl->pending_pkts)) {
 		write_unlock_irq(&mhi_cntrl->pm_lock);
+		dev_err(dev, "DEBUG: suspend busy (recheck): dev_wake: %d pending_pkts: %d\n",
+			atomic_read(&mhi_cntrl->dev_wake),
+			atomic_read(&mhi_cntrl->pending_pkts));
 		return -EBUSY;
 	}
 
-- 
2.45.2