[PATCHv2 2/2] pci: warn if a running device is unaware of reset

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

If a reset is issued to a running device with a driver that didn't
register the notification callbacks, the driver may be unaware of this
event and have an inconsistent view of the device's state. Log a warning
of this event because there's nothing else indicating the event occured,
which could be confusing when debugging such situations.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 drivers/pci/pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 338dfcd983f1e..bbf12d4998269 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5158,6 +5158,8 @@ static void pci_dev_save_and_disable(struct pci_dev *dev)
 	 */
 	if (err_handler && err_handler->reset_prepare)
 		err_handler->reset_prepare(dev);
+	else if (dev->driver)
+		pci_warn(dev, "resetting");
 
 	/*
 	 * Wake-up device prior to save.  PM registers default to D0 after
@@ -5191,6 +5193,8 @@ static void pci_dev_restore(struct pci_dev *dev)
 	 */
 	if (err_handler && err_handler->reset_done)
 		err_handler->reset_done(dev);
+	else if (dev->driver)
+		pci_warn(dev, "reset done");
 }
 
 /* dev->reset_methods[] is a 0-terminated list of indices into this array */
-- 
2.43.5