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authorAlan Stern <stern@rowland.harvard.edu>2011-07-15 17:22:15 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-08 10:23:09 -0700
commit6691c4c32de7046a36cd94b2f904507dcfb86de7 (patch)
tree6b944845f50787aab0365c5cf3d3d9d1e87e7821
parent51faabb807245bd12d026660d8957168df64abef (diff)
downloadlinux-linaro-stable-6691c4c32de7046a36cd94b2f904507dcfb86de7.tar.gz
USB: OHCI: fix another regression for NVIDIA controllers
commit 6ea12a04d295235ed67010a09fdea58c949e3eb0 upstream. The NVIDIA series of OHCI controllers continues to be troublesome. A few people using the MCP67 chipset have reported that even with the most recent kernels, the OHCI controller fails to handle new connections and spams the system log with "unable to enumerate USB port" messages. This is different from the other problems previously reported for NVIDIA OHCI controllers, although it is probably related. It turns out that the MCP67 controller does not like to be kept in the RESET state very long. After only a few seconds, it decides not to work any more. This patch (as1479) changes the PCI initialization quirk code so that NVIDIA controllers are switched into the SUSPEND state after 50 ms of RESET. With no interrupts enabled and all the downstream devices reset, and thus unable to send wakeup requests, this should be perfectly safe (even for non-NVIDIA hardware). The removal code in ohci-hcd hasn't been changed; it will still leave the controller in the RESET state. As a result, if someone unloads ohci-hcd and then reloads it, the controller won't work again until the system is rebooted. If anybody complains about this, the removal code can be updated similarly. This fixes Bugzilla #22052. Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/host/pci-quirks.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 464ed977b45d..bcf7a88fe516 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -34,6 +34,8 @@
#define OHCI_INTRSTATUS 0x0c
#define OHCI_INTRENABLE 0x10
#define OHCI_INTRDISABLE 0x14
+#define OHCI_FMINTERVAL 0x34
+#define OHCI_HCR (1 << 0) /* host controller reset */
#define OHCI_OCR (1 << 3) /* ownership change request */
#define OHCI_CTRL_RWC (1 << 9) /* remote wakeup connected */
#define OHCI_CTRL_IR (1 << 8) /* interrupt routing */
@@ -204,6 +206,32 @@ static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
/* reset controller, preserving RWC (and possibly IR) */
writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
+ readl(base + OHCI_CONTROL);
+
+ /* Some NVIDIA controllers stop working if kept in RESET for too long */
+ if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) {
+ u32 fminterval;
+ int cnt;
+
+ /* drive reset for at least 50 ms (7.1.7.5) */
+ msleep(50);
+
+ /* software reset of the controller, preserving HcFmInterval */
+ fminterval = readl(base + OHCI_FMINTERVAL);
+ writel(OHCI_HCR, base + OHCI_CMDSTATUS);
+
+ /* reset requires max 10 us delay */
+ for (cnt = 30; cnt > 0; --cnt) { /* ... allow extra time */
+ if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
+ break;
+ udelay(1);
+ }
+ writel(fminterval, base + OHCI_FMINTERVAL);
+
+ /* Now we're in the SUSPEND state with all devices reset
+ * and wakeups and interrupts disabled
+ */
+ }
/*
* disable interrupts