[ 022/147] xhci: Warn when hosts dont halt.

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>

commit 5af98bb06dee79d28c805f9fd0805ce791121784 upstream.

Eric Fu reports a problem with his VIA host controller fetching a zeroed
event ring pointer on resume from suspend.  The host should have been
halted, but we can't be sure because that code ignores the return value
from xhci_halt().  Print a warning when the host controller refuses to
halt within XHCI_MAX_HALT_USEC (currently 16 seconds).

(Update: it turns out that the VIA host controller is reporting a halted
state when it fetches the zeroed event ring pointer.  However, we still
need this warning for other host controllers.)

Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/host/xhci.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e1963d4..f68bc15 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -106,6 +106,9 @@ int xhci_halt(struct xhci_hcd *xhci)
 			STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
 	if (!ret)
 		xhci->xhc_state |= XHCI_STATE_HALTED;
+	else
+		xhci_warn(xhci, "Host not halted after %u microseconds.\n",
+				XHCI_MAX_HALT_USEC);
 	return ret;
 }
 


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