xhci-tegra: t210: wait for U3 entry in bus suspend

In T210, U3 entry delay is expected as LFPS dectector WAR needs to
use two mailbox commands to implement. The two mailbox commands can be
finished among 2 ms most of time. But, in worst case, they may
take up to hundreds of ms. Waiting for U3 entry in bus suspend
for some time can avoid xhci-tegra driver to stop system suspend
for long U3 entry delay frequently.

Bug 200227198

Change-Id: I989e60e829d8bd9b085495d96f70580c6d7981ab
Signed-off-by: Henry Lin <henryl@nvidia.com>
Reviewed-on: http://git-master/r/1202561
(cherry picked from commit 0c9facf9ed457262e4e09994a920d5fbf547359d)
Reviewed-on: http://git-master/r/1206882
Tested-by: Rajkumar Kasirajan <rkasirajan@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Winnie Hsu <whsu@nvidia.com>

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index 9eb1021cdbf82ea74e1935ddf5057f92cdf2f186..d6560c72ff9f03e58c8d6b4d0f97fa49ecba95b5 100644 (file)
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -3939,6 +3939,35 @@ static int tegra_xhci_request_irq(struct platform_device *pdev,
        return 0;
 }
 
+static void get_rootport_name(struct xhci_hcd *xhci, int port_id, char *name,
+                               int size)
+{
+       struct usb_hcd *hcd;
+       int i, num;
+       __le32 __iomem **ports;
+       __le32 __iomem *addr;
+       u32 portsc;
+
+       portsc = xhci_read_portsc(xhci, port_id);
+       if (DEV_SUPERSPEED(portsc)) {
+               hcd = xhci->shared_hcd;
+               ports = xhci->usb3_ports;
+               num = xhci->num_usb3_ports;
+       } else {
+               hcd = xhci->main_hcd;
+               ports = xhci->usb2_ports;
+               num = xhci->num_usb2_ports;
+       }
+
+       addr = &xhci->op_regs->port_status_base + NUM_PORT_REGS * port_id;
+       for (i = 0; i < num; i++) {
+               if (ports[i] == addr)
+                       break;
+       }
+
+       snprintf(name, size, "%d-%d", hcd->self.busnum, i + 1);
+}
+
 #ifdef CONFIG_PM
 static int tegra_xhci_bus_suspend(struct usb_hcd *hcd)
 {
@@ -3950,7 +3979,6 @@ static int tegra_xhci_bus_suspend(struct usb_hcd *hcd)
        int num_ports = HCS_MAX_PORTS(xhci->hcs_params1);
        u32 usbcmd;
        int i;
-       u32 portsc;
 
        mutex_lock(&tegra->sync_lock);
 
@@ -3986,17 +4014,52 @@ static int tegra_xhci_bus_suspend(struct usb_hcd *hcd)
        usbcmd = xhci_readl(xhci, &xhci->op_regs->command);
        usbcmd &= ~CMD_EIE;
        xhci_writel(xhci, usbcmd, &xhci->op_regs->command);
+
        for (i = 0; i < num_ports; i++) {
+               struct device *dev;
+               bool is_busy = true;
+               char devname[16];
+               u32 portsc;
+
                portsc = xhci_read_portsc(xhci, i);
-               if ((portsc & PORT_PE) && (portsc & PORT_PLS_MASK) != XDEV_U3) {
+
+               if (!(portsc & PORT_PE))
+                       continue;
+
+               if ((portsc & PORT_PLS_MASK) == XDEV_U3)
+                       continue;
+
+               dev = &tegra->pdev->dev;
+               get_rootport_name(xhci, i, devname, sizeof(devname));
+#if defined(CONFIG_ARCH_TEGRA_21x_SOC)
+               if (DEV_SUPERSPEED(portsc)) {
+                       unsigned long end = jiffies + msecs_to_jiffies(200);
+                       while (time_before(jiffies, end)) {
+                               if ((portsc & PORT_PLS_MASK) == XDEV_RESUME)
+                                       break;
+                               spin_unlock_irqrestore(&xhci->lock, flags);
+                               msleep(20);
+                               spin_lock_irqsave(&xhci->lock, flags);
+                               portsc = xhci_read_portsc(xhci, i);
+                               if ((portsc & PORT_PLS_MASK) == XDEV_U3) {
+                                       dev_info(dev, "%s is suspended\n",
+                                               devname);
+                                       is_busy = false;
+                                       break;
+                               }
+                       }
+               }
+#endif
+               if (is_busy) {
                        usbcmd = xhci_readl(xhci, &xhci->op_regs->command);
                        usbcmd |= CMD_EIE;
                        xhci_writel(xhci, usbcmd, &xhci->op_regs->command);
 
                        spin_unlock_irqrestore(&xhci->lock, flags);
 
-                       xhci_info(xhci, "%s: port not in suspended state\n",
-                               __func__);
+                       dev_info(dev, "%s is not suspended: %08x\n", devname,
+                               portsc);
+
                        err = -EBUSY;
                        goto xhci_bus_suspend_failed;
                }