[3.5.y.z extended stable] Patch "xhci: quirk for extra long delay for S4" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    xhci: quirk for extra long delay for S4

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From b32bbeac32ba85b7cbe3e5ecdf178bf02c5e5216 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum at suse.de>
Date: Mon, 30 Sep 2013 15:50:54 +0200
Subject: [PATCH] xhci: quirk for extra long delay for S4

commit 455f58925247e8a1a1941e159f3636ad6ee4c90b upstream.

It has been reported that this chipset really cannot
sleep without this extraordinary delay.

This patch should be backported, in order to ensure this host functions
under stable kernels.  The last quirk for Fresco Logic hosts (commit
bba18e33f25072ebf70fd8f7f0cdbf8cdb59a746 "xhci: Extend Fresco Logic MSI
quirk.") was backported to stable kernels as old as 2.6.36.

Signed-off-by: Oliver Neukum <oneukum at suse.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp at linux.intel.com>
[ luis: backported to 3.5:
  - adjusted context
  - replaced usage of xhci_dbg_trace() by xhci_dbg() ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/host/xhci-pci.c | 8 ++++++++
 drivers/usb/host/xhci.c     | 7 ++++++-
 drivers/usb/host/xhci.h     | 1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 5e3ef3e..8b218a4 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -67,6 +67,14 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 			xhci_dbg(xhci, "QUIRK: Fresco Logic xHC needs configure"
 					" endpoint cmd after reset endpoint\n");
 		}
+		if (pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK &&
+				pdev->revision == 0x4) {
+			xhci->quirks |= XHCI_SLOW_SUSPEND;
+			xhci_dbg(xhci,
+				 "QUIRK: Fresco Logic xHC revision %u"
+				 "must be suspended extra slowly",
+				 pdev->revision);
+		}
 		/* Fresco Logic confirms: all revisions of this chip do not
 		 * support MSI, even though some of them claim to in their PCI
 		 * capabilities.
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index eb31daa..10e10a6 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -883,6 +883,7 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci)
 int xhci_suspend(struct xhci_hcd *xhci)
 {
 	int			rc = 0;
+	unsigned int		delay = XHCI_MAX_HALT_USEC;
 	struct usb_hcd		*hcd = xhci_to_hcd(xhci);
 	u32			command;

@@ -901,8 +902,12 @@ int xhci_suspend(struct xhci_hcd *xhci)
 	command = xhci_readl(xhci, &xhci->op_regs->command);
 	command &= ~CMD_RUN;
 	xhci_writel(xhci, command, &xhci->op_regs->command);
+
+	/* Some chips from Fresco Logic need an extraordinary delay */
+	delay *= (xhci->quirks & XHCI_SLOW_SUSPEND) ? 10 : 1;
+
 	if (handshake(xhci, &xhci->op_regs->status,
-		      STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC)) {
+		      STS_HALT, STS_HALT, delay)) {
 		xhci_warn(xhci, "WARN: xHC CMD_RUN timeout\n");
 		spin_unlock_irq(&xhci->lock);
 		return -ETIMEDOUT;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 9a97918..b15d034 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1517,6 +1517,7 @@ struct xhci_hcd {
 #define XHCI_COMP_MODE_QUIRK	(1 << 14)
 #define XHCI_AVOID_BEI		(1 << 15)
 #define XHCI_PLAT		(1 << 16)
+#define XHCI_SLOW_SUSPEND	(1 << 17)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */
--
1.8.3.2