[PATCH 3.12 057/146] USB: OHCI: fix problem with global suspend on ATI controllers

Jiri Slaby
2014-06-09T09:11:54Z

From: Alan Stern <stern@rowland.harvard.edu>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit c1db30a2a79eb59997b13b8cabf2a50bea9f04e1 upstream.

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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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(+)

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 2347ab83f046..dcf570862502 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 659cde1ed1ea..fd9f77bcd499 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 e2e5faa5a402..0b2e58c2dfef 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 */
--
1.9.3