1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c
index 992d963b91fc..8905ba4e482a 100644
--- a/drivers/usb/host/ehci-omap.c
+++ b/drivers/usb/host/ehci-omap.c
@@ -116,6 +116,8 @@
 #define OMAP_UHH_DEBUG_CSR                              (0x44)
 
 /* EHCI Register Set */
+#define EHCI_INSNREG04                                  (0xA0)
+#define EHCI_INSNREG04_DISABLE_UNSUSPEND                (1 << 5)
 #define EHCI_INSNREG05_ULPI                             (0xA4)
 #define EHCI_INSNREG05_ULPI_CONTROL_SHIFT               31
 #define EHCI_INSNREG05_ULPI_PORTSEL_SHIFT               24
@@ -382,6 +384,18 @@ static int omap_start_ehc(struct ehci_hcd_omap *omap, struct usb_hcd *hcd)
         dev_dbg(omap->dev, "UHH setup done, uhh_hostconfig=%x\n", reg);
 
 
+        /*
+         * An undocumented "feature" in the OMAP3 EHCI controller,
+         * causes suspended ports to be taken out of suspend when
+         * the USBCMD.Run/Stop bit is cleared (for example when
+         * we do ehci_bus_suspend).
+         * This breaks suspend-resume if the root-hub is allowed
+         * to suspend. Writing 1 to this undocumented register bit
+         * disables this feature and restores normal behavior.
+         */
+        ehci_omap_writel(omap->ehci_base, EHCI_INSNREG04,
+                                EHCI_INSNREG04_DISABLE_UNSUSPEND);
+
         if ((omap->port_mode[0] == EHCI_HCD_OMAP_MODE_TLL) ||
                 (omap->port_mode[1] == EHCI_HCD_OMAP_MODE_TLL) ||
                         (omap->port_mode[2] == EHCI_HCD_OMAP_MODE_TLL)) {