USB: OHCI: fix problem with global suspend on ATI controllers
Some OHCI controllers from ATI/AMD seem to have difficulty with
"global" USB suspend, that is, suspending an entire USB bus without
setting the suspend feature for each port connected to a device. When
we try to resume the child devices, the controller gives timeout
errors on the unsuspended ports, requiring resets, and can even cause
ohci-hcd to hang; see
http://marc.info/?l=linux-usb&m=139514332820398&w=2
and the following messages.
This patch fixes the problem by adding a new quirk flag to ohci-hcd.
The flag causes the ohci_rh_suspend() routine to suspend each
unsuspended, enabled port before suspending the root hub. This
effectively converts the "global" suspend to an ordinary root-hub
suspend. There is no need to unsuspend these ports when the root hub
is resumed, because the child devices will be resumed anyway in the
course of a normal system resume ("global" suspend is never used for
runtime PM).
This patch should be applied to all stable kernels which include
commit 0aa2832dd0d9 (USB: use "global suspend" for system sleep on
USB-2 buses) or a backported version thereof.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Peter Münster <pmlists@free.fr>
Tested-by: Peter Münster <pmlists@free.fr>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index c81c872..cd871b8 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -90,6 +90,24 @@
dl_done_list (ohci);
finish_unlinks (ohci, ohci_frame_no(ohci));
+ /*
+ * Some controllers don't handle "global" suspend properly if
+ * there are unsuspended ports. For these controllers, put all
+ * the enabled ports into suspend before suspending the root hub.
+ */
+ if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
+ __hc32 __iomem *portstat = ohci->regs->roothub.portstatus;
+ int i;
+ unsigned temp;
+
+ for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
+ temp = ohci_readl(ohci, portstat);
+ if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
+ RH_PS_PES)
+ ohci_writel(ohci, RH_PS_PSS, portstat);
+ }
+ }
+
/* maybe resume can wake root hub */
if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
ohci->hc_control |= OHCI_CTRL_RWE;