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>

3 files changed, 21 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index c81c8721cc5a..cd871b895013 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -90,6 +90,24 @@ __acquires(ohci->lock)
         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;
diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index 90879e9ccbec..bb1509675727 100644
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -160,6 +160,7 @@ static int ohci_quirk_amd700(struct usb_hcd *hcd)
                 ohci_dbg(ohci, "enabled AMD prefetch quirk\n");
         }
 
+        ohci->flags |= OHCI_QUIRK_GLOBAL_SUSPEND;
         return 0;
 }
 
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 9250cada13f0..4550ce05af7f 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -405,6 +405,8 @@ struct ohci_hcd {
 #define OHCI_QUIRK_HUB_POWER    0x100                   /* distrust firmware power/oc setup */
 #define OHCI_QUIRK_AMD_PLL      0x200                   /* AMD PLL quirk*/
 #define OHCI_QUIRK_AMD_PREFETCH 0x400                   /* pre-fetch for ISO transfer */
+#define OHCI_QUIRK_GLOBAL_SUSPEND       0x800           /* must suspend ports */
+
         // there are also chip quirks/bugs in init logic
 
         struct work_struct      nec_work;       /* Worker for NEC quirk */