[PATCH] USB: Switch isp116x-hcd over to root hub interrupt

Switch isp116x-hcd over from root hub polling to interrupt.  This change closes
also a race that was present with the old polling scheme: status polling could
happen in a time window, where root hub status bits were not stable.

Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 22 insertions, 13 deletions

diff --git a/drivers/usb/host/isp116x-hcd.c b/drivers/usb/host/isp116x-hcd.c
index 1ed2abac8d17..41bbae83fc71 100644
--- a/drivers/usb/host/isp116x-hcd.c
+++ b/drivers/usb/host/isp116x-hcd.c
@@ -83,7 +83,7 @@
 #include "../core/hcd.h"
 #include "isp116x.h"
 
-#define DRIVER_VERSION  "08 Apr 2005"
+#define DRIVER_VERSION  "05 Aug 2005"
 #define DRIVER_DESC     "ISP116x USB Host Controller Driver"
 
 MODULE_DESCRIPTION(DRIVER_DESC);
@@ -629,14 +629,12 @@ static irqreturn_t isp116x_irq(struct usb_hcd *hcd, struct pt_regs *regs)
                         ERR("Unrecoverable error\n");
                         /* What should we do here? Reset?  */
                 }
-                if (intstat & HCINT_RHSC) {
-                        isp116x->rhstatus =
-                            isp116x_read_reg32(isp116x, HCRHSTATUS);
-                        isp116x->rhport[0] =
-                            isp116x_read_reg32(isp116x, HCRHPORT1);
-                        isp116x->rhport[1] =
-                            isp116x_read_reg32(isp116x, HCRHPORT2);
-                }
+                if (intstat & HCINT_RHSC)
+                        /* When root hub or any of its ports is going
+                           to come out of suspend, it may take more
+                           than 10ms for status bits to stabilize. */
+                        mod_timer(&hcd->rh_timer, jiffies
+                                  + msecs_to_jiffies(20) + 1);
                 if (intstat & HCINT_RD) {
                         DBG("---- remote wakeup\n");
                         schedule_work(&isp116x->rh_resume);
@@ -925,20 +923,27 @@ static int isp116x_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
         struct isp116x *isp116x = hcd_to_isp116x(hcd);
         int ports, i, changed = 0;
+        unsigned long flags;
 
         if (!HC_IS_RUNNING(hcd->state))
                 return -ESHUTDOWN;
 
-        ports = isp116x->rhdesca & RH_A_NDP;
+        /* Report no status change now, if we are scheduled to be
+           called later */
+        if (timer_pending(&hcd->rh_timer))
+                return 0;
 
-        /* init status */
+        ports = isp116x->rhdesca & RH_A_NDP;
+        spin_lock_irqsave(&isp116x->lock, flags);
+        isp116x->rhstatus = isp116x_read_reg32(isp116x, HCRHSTATUS);
         if (isp116x->rhstatus & (RH_HS_LPSC | RH_HS_OCIC))
                 buf[0] = changed = 1;
         else
                 buf[0] = 0;
 
         for (i = 0; i < ports; i++) {
-                u32 status = isp116x->rhport[i];
+                u32 status = isp116x->rhport[i] =
+                    isp116x_read_reg32(isp116x, i ? HCRHPORT2 : HCRHPORT1);
 
                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
                               | RH_PS_OCIC | RH_PS_PRSC)) {
@@ -947,6 +952,7 @@ static int isp116x_hub_status_data(struct usb_hcd *hcd, char *buf)
                         continue;
                 }
         }
+        spin_unlock_irqrestore(&isp116x->lock, flags);
         return changed;
 }
 
@@ -1536,6 +1542,9 @@ static int isp116x_start(struct usb_hcd *hcd)
                 return -ENODEV;
         }
 
+        /* To be removed in future */
+        hcd->uses_new_polling = 1;
+
         isp116x_write_reg16(isp116x, HCITLBUFLEN, ISP116x_ITL_BUFSIZE);
         isp116x_write_reg16(isp116x, HCATLBUFLEN, ISP116x_ATL_BUFSIZE);
 
@@ -1639,7 +1648,7 @@ static int __init_or_module isp116x_remove(struct device *dev)
         struct platform_device *pdev;
         struct resource *res;
 
-        if(!hcd)
+        if (!hcd)
                 return 0;
         isp116x = hcd_to_isp116x(hcd);
         pdev = container_of(dev, struct platform_device, dev);