USB: EHCI: create a "periodic schedule info" struct

This patch begins the process of unifying the scheduling parameters
that ehci-hcd uses for interrupt and isochronous transfers.  It
creates an ehci_per_sched structure, which will be stored in both
ehci_qh and ehci_iso_stream structures, and will contain the common
scheduling information needed for both.

Initially we merely create the new structure and move some existing
fields into it.  Later patches will add more fields and utilize these
structures in improved scheduling algorithms.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 16 insertions, 13 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index b93eb59bb529..e2b64c40d94f 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -54,6 +54,19 @@ struct ehci_stats {
         unsigned long           unlink;
 };
 
+/*
+ * Scheduling and budgeting information for periodic transfers, for both
+ * high-speed devices and full/low-speed devices lying behind a TT.
+ */
+struct ehci_per_sched {
+        struct usb_device       *udev;          /* access to the TT */
+        struct usb_host_endpoint *ep;
+        u16                     tt_usecs;       /* time on the FS/LS bus */
+        u16                     period;         /* actual period in frames */
+        u16                     phase;          /* actual phase, frame part */
+        u8                      phase_uf;       /* uframe part of the phase */
+        u8                      usecs, c_usecs; /* times on the HS bus */
+};
 #define NO_FRAME        29999                   /* frame not assigned yet */
 
 /* ehci_hcd->lock guards shared data against other CPUs:
@@ -387,6 +400,7 @@ struct ehci_qh {
         struct list_head        intr_node;      /* list of intr QHs */
         struct ehci_qtd         *dummy;
         struct list_head        unlink_node;
+        struct ehci_per_sched   ps;             /* scheduling info */
 
         unsigned                unlink_cycle;
 
@@ -400,15 +414,8 @@ struct ehci_qh {
         u8                      xacterrs;       /* XactErr retry counter */
 #define QH_XACTERR_MAX          32              /* XactErr retry limit */
 
-        /* periodic schedule info */
-        u8                      usecs;          /* intr bandwidth */
         u8                      gap_uf;         /* uframes split/csplit gap */
-        u8                      c_usecs;        /* ... split completion bw */
-        u16                     tt_usecs;       /* tt downstream bandwidth */
-        unsigned short          period;         /* polling interval */
-        unsigned short          start;          /* where polling starts */
 
-        struct usb_device       *dev;           /* access to TT */
         unsigned                is_out:1;       /* bulk or intr OUT */
         unsigned                clearing_tt:1;  /* Clear-TT-Buf in progress */
         unsigned                dequeue_during_giveback:1;
@@ -451,20 +458,16 @@ struct ehci_iso_stream {
         u8                      highspeed;
         struct list_head        td_list;        /* queued itds/sitds */
         struct list_head        free_list;      /* list of unused itds/sitds */
-        struct usb_device       *udev;
-        struct usb_host_endpoint *ep;
 
         /* output of (re)scheduling */
+        struct ehci_per_sched   ps;             /* scheduling info */
         unsigned                next_uframe;
         __hc32                  splits;
 
         /* the rest is derived from the endpoint descriptor,
-         * trusting urb->interval == f(epdesc->bInterval) and
          * including the extra info for hw_bufp[0..2]
          */
-        u8                      usecs, c_usecs;
-        u16                     interval;
-        u16                     tt_usecs;
+        u16                     uperiod;        /* period in uframes */
         u16                     maxp;
         u16                     raw_mask;
         unsigned                bandwidth;