hw/usb-ohci.c: Fix handling of remote wakeup corner cases
Correct a number of minor errors in the OHCI wakeup implementation:
* when the port is suspended but the controller is not, raise RHSC
* when the controller is suspended but the port is not, raise RD
* when the controller is suspended, move it to resume state
These fix some edge cases where a USB device might not successfully get
the attention of the guest OS if it tried to do so at the wrong time.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/hw/usb-ohci.c b/hw/usb-ohci.c
index 5d2ae01..1c29b9f 100644
--- a/hw/usb-ohci.c
+++ b/hw/usb-ohci.c
@@ -373,14 +373,25 @@
OHCIState *s = container_of(bus, OHCIState, bus);
int portnum = dev->port->index;
OHCIPort *port = &s->rhport[portnum];
+ uint32_t intr = 0;
if (port->ctrl & OHCI_PORT_PSS) {
DPRINTF("usb-ohci: port %d: wakeup\n", portnum);
port->ctrl |= OHCI_PORT_PSSC;
port->ctrl &= ~OHCI_PORT_PSS;
- if ((s->ctl & OHCI_CTL_HCFS) == OHCI_USB_SUSPEND) {
- ohci_set_interrupt(s, OHCI_INTR_RD);
- }
+ intr = OHCI_INTR_RHSC;
}
+ /* Note that the controller can be suspended even if this port is not */
+ if ((s->ctl & OHCI_CTL_HCFS) == OHCI_USB_SUSPEND) {
+ DPRINTF("usb-ohci: remote-wakeup: SUSPEND->RESUME\n");
+ /* This is the one state transition the controller can do by itself */
+ s->ctl &= ~OHCI_CTL_HCFS;
+ s->ctl |= OHCI_USB_RESUME;
+ /* In suspend mode only ResumeDetected is possible, not RHSC:
+ * see the OHCI spec 5.1.2.3.
+ */
+ intr = OHCI_INTR_RD;
+ }
+ ohci_set_interrupt(s, intr);
}
/* Reset the controller */
