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 <st...@rowland.harvard.edu>
Reported-by: Peter Münster <pmli...@free.fr>
Tested-by: Peter Münster <pmli...@free.fr>
CC: <sta...@vger.kernel.org>
---
[as1746]
drivers/usb/host/ohci-hub.c | 18 ++++++++++++++++++
drivers/usb/host/ohci-pci.c | 1 +
drivers/usb/host/ohci.h | 2 ++
3 files changed, 21 insertions(+)
Index: usb-3.15/drivers/usb/host/ohci-hub.c
===================================================================
--- usb-3.15.orig/drivers/usb/host/ohci-hub.c
+++ usb-3.15/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;
Index: usb-3.15/drivers/usb/host/ohci-pci.c
===================================================================
--- usb-3.15.orig/drivers/usb/host/ohci-pci.c
+++ usb-3.15/drivers/usb/host/ohci-pci.c
@@ -160,6 +160,7 @@ static int ohci_quirk_amd700(struct usb_
ohci_dbg(ohci, "enabled AMD prefetch quirk\n");
}
+ ohci->flags |= OHCI_QUIRK_GLOBAL_SUSPEND;
return 0;
}
Index: usb-3.15/drivers/usb/host/ohci.h
===================================================================
--- usb-3.15.orig/drivers/usb/host/ohci.h
+++ usb-3.15/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 */
--
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