Use the correct formulas and values for calculating the bittime within
a frame.
Signed-off-by: Grant Likely <[EMAIL PROTECTED]>
---
drivers/usb/c67x00/c67x00-hcd.h | 10 ++++++--
drivers/usb/c67x00/c67x00-sched.c | 42 +++++++++++++++++++++++++++++++++---
2 files changed, 45 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/c67x00/c67x00-hcd.h b/drivers/usb/c67x00/c67x00-hcd.h
index 8f8eff1..94ce7ec 100644
--- a/drivers/usb/c67x00/c67x00-hcd.h
+++ b/drivers/usb/c67x00/c67x00-hcd.h
@@ -46,12 +46,16 @@
* The current implementation switches between _STD (default) and _ISO (when
* isochronous transfers are scheduled), in order to optimize the throughput
* in normal cicrumstances, but also provide good isochronous behaviour.
+ *
+ * Bandwidth is described in bit time so with a 12MHz USB clock and 1ms
+ * frames; there are 12000 bit times per frame.
*/
-#define MAX_FRAME_BW_STD 4000
-#define MAX_FRAME_BW_ISO 2400
+#define TOTAL_FRAME_BW 12000
+#define DEFAULT_EOT 2250
-#define DEFAULT_EOT 6500
+#define MAX_FRAME_BW_STD (TOTAL_FRAME_BW - DEFAULT_EOT)
+#define MAX_FRAME_BW_ISO 2400
/*
* Periodic transfers may only use 90% of the full frame, but as
diff --git a/drivers/usb/c67x00/c67x00-sched.c
b/drivers/usb/c67x00/c67x00-sched.c
index 952bdab..0d08af7 100644
--- a/drivers/usb/c67x00/c67x00-sched.c
+++ b/drivers/usb/c67x00/c67x00-sched.c
@@ -520,11 +520,45 @@ static inline void giveback_urb(struct c67x00_hcd
*c67x00, struct urb *urb,
/* --------------------------------------------------------------------------
*/
-static int claim_frame_bw(struct c67x00_hcd *c67x00, int len, int periodic)
+static int claim_frame_bw(struct c67x00_hcd *c67x00, struct urb *urb,
+ int len, int periodic)
{
- int bit_time = len * 8;
+ struct urb_priv *urbp = urb->hcpriv;
+ int bit_time;
+
+ /* According to the C67x00 BIOS user manual, page 3-18,19, the
+ * following calculations provide the full speed bit times for
+ * a transaction.
+ *
+ * FS(in) = 112.5 + 9.36*BC + HOST_DELAY
+ * FS(in,iso) = 90.5 + 9.36*BC + HOST_DELAY
+ * FS(out) = 112.5 + 9.36*BC + HOST_DELAY
+ * FS(out,iso) = 78.4 + 9.36*BC + HOST_DELAY
+ * LS(in) = 802.4 + 75.78*BC + HOST_DELAY
+ * LS(out) = 802.6 + 74.67*BC + HOST_DELAY
+ *
+ * HOST_DELAY == 106 for the c67200 and c67300.
+ */
+
+ /* make calculations in 1/100 bit times to maintain resolution */
+ if (urbp->ep_data->dev->speed == USB_SPEED_LOW) {
+ /* Low speed pipe */
+ if (usb_pipein(urb->pipe))
+ bit_time = 80240 + 7578*len;
+ else
+ bit_time = 80260 + 7467*len;
+ } else {
+ /* FS pipes */
+ if (usb_pipeisoc(urb->pipe))
+ bit_time = usb_pipein(urb->pipe) ? 9050 : 7840;
+ else
+ bit_time = 11250;
+ bit_time += 936*len;
+ }
- /* TODO don't we need to take low speed into regards? */
+ /* Scale back down to integer bit times. Use a host delay of 106.
+ * (this is the only place it is used) */
+ bit_time = ((bit_time+50) / 100) + 106;
if (unlikely(bit_time + c67x00->bandwidth_allocated >=
c67x00->max_frame_bw))
@@ -565,7 +599,7 @@ static int create_td(struct c67x00_hcd *c67x00,
__u8 cmd = 0;
int tt = 0;
- if (claim_frame_bw(c67x00, len,
+ if (claim_frame_bw(c67x00, urb, len,
usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)))
return -EMSGSIZE; /* Not really an error, but expected */
--
1.4.4.2
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