diff mbox series

[v2,2/5] thunderbolt: Do not resume routers if UID is not set

Message ID 20220303131328.4150454-2-mario.limonciello@amd.com (mailing list archive)
State Accepted
Commit a283de3ec646f19b09f3c8e4c8f57c0e017c9b2b
Headers show
Series [v2,1/5] thunderbolt: Retry DROM reads for more failure scenarios | expand

Commit Message

Mario Limonciello March 3, 2022, 1:13 p.m. UTC 
Routers might not have a UID set if the DROM read failed during
initialization previously.

Normally upon resume the UID is re-read to confirm it's the same
device connected.
* If the DROM read failed during init but then succeeded during
  resume it could either be a new device or faulty device
* If the DROM read failed during init and also failed during resume
  it might be a different device plugged in all together.

Detect this situation and prevent re-using the same configuration in
these cirucmstances.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v1->v2:
 * Update commit message
 drivers/thunderbolt/switch.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index b5fb3e76ed09..294518af4ee4 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -2980,6 +2980,10 @@  int tb_switch_resume(struct tb_switch *sw)
 			return err;
 		}
 
+		/* We don't have any way to confirm this was the same device */
+		if (!sw->uid)
+			return -ENODEV;
+
 		if (tb_switch_is_usb4(sw))
 			err = usb4_switch_read_uid(sw, &uid);
 		else