We can't halt the secondary HCD, because it's also the primary HCD,
which will cause problems if we have devices attached to the primary
HCD, like a keyboard.
We've been carrying this in our Linux-as-a-bootloader environment for a little
while now. The machines all have the same TI TUSB73x0 part, and when we kexec
the devices don't come back until a system power cycle.
I'd like some advice on an acceptable way to upstream the fix, so that the xhci
device survives kexec.
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/usb/host/xhci.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index adc169d2fd76..ec92a843325b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -682,6 +682,21 @@ void xhci_stop(struct usb_hcd *hcd)
mutex_lock(&xhci->mutex);
+ /*
+ * We can't halt the secondary HCD, because it's also the primary
+ * HCD, which will cause problems if we have devices attached to the
+ * primary HCD, like a keyboard.
+ */
+ if (!usb_hcd_is_primary_hcd(hcd)) {
+ /* The shared_hcd is going to be deallocated shortly (the USB
+ * core only calls this function when allocation fails in
+ * usb_add_hcd(), or usb_remove_hcd() is called). So we need
+ * to unset xHCI's pointer. */
+ xhci->shared_hcd = NULL;
+ mutex_unlock(&xhci->mutex);
+ return;
+ }
+
if (!(xhci->xhc_state & XHCI_STATE_HALTED)) {
spin_lock_irq(&xhci->lock);
@@ -693,11 +708,6 @@ void xhci_stop(struct usb_hcd *hcd)
spin_unlock_irq(&xhci->lock);
}
- if (!usb_hcd_is_primary_hcd(hcd)) {
- mutex_unlock(&xhci->mutex);
- return;
- }
-
xhci_cleanup_msix(xhci);
/* Deleting Compliance Mode Recovery Timer */
--
2.9.3
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
