USB: EHCI update VIA workaround

This revamps handling of the hardware "async advance" IRQ, and its watchdog
timer.  Basically it dis-entangles that important timeout from the others,
simplifying the associated state and code to make it more robust.

This reportedly improves behavior of EHCI on some systems with VIA chips,
and AFAIK won't affect non-VIA hardware.  VIA systems need this code to
recover from silcon bugs whereby the "async advance" IRQ isn't issued.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index bbc3082a73d7..6aac39f50e07 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -58,7 +58,6 @@ struct ehci_hcd {			/* one per controller */
         /* async schedule support */
         struct ehci_qh          *async;
         struct ehci_qh          *reclaim;
-        unsigned                reclaim_ready : 1;
         unsigned                scanning : 1;
 
         /* periodic schedule support */
@@ -81,6 +80,7 @@ struct ehci_hcd {			/* one per controller */
         struct dma_pool         *itd_pool;      /* itd per iso urb */
         struct dma_pool         *sitd_pool;     /* sitd per split iso urb */
 
+        struct timer_list       iaa_watchdog;
         struct timer_list       watchdog;
         unsigned long           actions;
         unsigned                stamp;
@@ -114,9 +114,21 @@ static inline struct usb_hcd *ehci_to_hcd (struct ehci_hcd *ehci)
 }
 
 
+static inline void
+iaa_watchdog_start (struct ehci_hcd *ehci)
+{
+        WARN_ON(timer_pending(&ehci->iaa_watchdog));
+        mod_timer (&ehci->iaa_watchdog,
+                        jiffies + msecs_to_jiffies(EHCI_IAA_MSECS));
+}
+
+static inline void iaa_watchdog_done (struct ehci_hcd *ehci)
+{
+        del_timer (&ehci->iaa_watchdog);
+}
+
 enum ehci_timer_action {
         TIMER_IO_WATCHDOG,
-        TIMER_IAA_WATCHDOG,
         TIMER_ASYNC_SHRINK,
         TIMER_ASYNC_OFF,
 };
@@ -134,9 +146,6 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
                 unsigned long t;
 
                 switch (action) {
-                case TIMER_IAA_WATCHDOG:
-                        t = EHCI_IAA_JIFFIES;
-                        break;
                 case TIMER_IO_WATCHDOG:
                         t = EHCI_IO_JIFFIES;
                         break;
@@ -153,8 +162,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
                 // async queue SHRINK often precedes IAA.  while it's ready
                 // to go OFF neither can matter, and afterwards the IO
                 // watchdog stops unless there's still periodic traffic.
-                if (action != TIMER_IAA_WATCHDOG
-                                && t > ehci->watchdog.expires
+                if (time_before_eq(t, ehci->watchdog.expires)
                                 && timer_pending (&ehci->watchdog))
                         return;
                 mod_timer (&ehci->watchdog, t);