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

Ben Hutchings
2012-10-14T14:46:13Z

From: Sarah Sharp <sarah.a.sharp@linux.intel.com>

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@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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;
}