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authorArvid Brodin <arvid.brodin@enea.com>2011-02-27 00:07:35 +0300
committerGreg Kroah-Hartman <gregkh@suse.de>2011-03-01 06:23:38 +0300
commit65f1b5255ce0e657e4d8de92098837d36831320a (patch)
treeccb5d598233a24c53d0a8303faae4bb7a2acf208 /drivers/usb/host/isp1760-hcd.c
parent6bda21bc0941c11f07cbf436ff6ca85e7e6e47f0 (diff)
downloadlinux-65f1b5255ce0e657e4d8de92098837d36831320a.tar.xz
usb/isp1760: Replace period calculation for INT packets with something readable
Replace the period calculation for INT packets with something readable. Seems to fix a rare bug with quickly repeated insertion/removal of several USB devices simultaneously (hub control INT packets). Signed-off-by: Arvid Brodin <arvid.brodin@enea.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/isp1760-hcd.c')
-rw-r--r--drivers/usb/host/isp1760-hcd.c106
1 files changed, 37 insertions, 69 deletions
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index 0f5b48946739..fd718ff6afab 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -97,9 +97,6 @@ struct isp1760_qh {
/* first part defined by EHCI spec */
struct list_head qtd_list;
- /* periodic schedule info */
- unsigned short period; /* polling interval */
-
u32 toggle;
u32 ping;
};
@@ -673,60 +670,51 @@ static void transform_into_atl(struct isp1760_qh *qh,
static void transform_add_int(struct isp1760_qh *qh,
struct isp1760_qtd *qtd, struct ptd *ptd)
{
- u32 maxpacket;
- u32 multi;
- u32 numberofusofs;
- u32 i;
- u32 usofmask, usof;
+ u32 usof;
u32 period;
- maxpacket = usb_maxpacket(qtd->urb->dev, qtd->urb->pipe,
- usb_pipeout(qtd->urb->pipe));
- multi = 1 + ((maxpacket >> 11) & 0x3);
- maxpacket &= 0x7ff;
- /* length of the data per uframe */
- maxpacket = multi * maxpacket;
-
- numberofusofs = qtd->urb->transfer_buffer_length / maxpacket;
- if (qtd->urb->transfer_buffer_length % maxpacket)
- numberofusofs += 1;
-
- usofmask = 1;
- usof = 0;
- for (i = 0; i < numberofusofs; i++) {
- usof |= usofmask;
- usofmask <<= 1;
- }
-
- if (qtd->urb->dev->speed != USB_SPEED_HIGH) {
- /* split */
- ptd->dw5 = 0x1c;
+ /*
+ * Most of this is guessing. ISP1761 datasheet is quite unclear, and
+ * the algorithm from the original Philips driver code, which was
+ * pretty much used in this driver before as well, is quite horrendous
+ * and, i believe, incorrect. The code below follows the datasheet and
+ * USB2.0 spec as far as I can tell, and plug/unplug seems to be much
+ * more reliable this way (fingers crossed...).
+ */
- if (qh->period >= 32)
- period = qh->period / 2;
+ if (qtd->urb->dev->speed == USB_SPEED_HIGH) {
+ /* urb->interval is in units of microframes (1/8 ms) */
+ period = qtd->urb->interval >> 3;
+
+ if (qtd->urb->interval > 4)
+ usof = 0x01; /* One bit set =>
+ interval 1 ms * uFrame-match */
+ else if (qtd->urb->interval > 2)
+ usof = 0x22; /* Two bits set => interval 1/2 ms */
+ else if (qtd->urb->interval > 1)
+ usof = 0x55; /* Four bits set => interval 1/4 ms */
else
- period = qh->period;
-
+ usof = 0xff; /* All bits set => interval 1/8 ms */
} else {
+ /* urb->interval is in units of frames (1 ms) */
+ period = qtd->urb->interval;
+ usof = 0x0f; /* Execute Start Split on any of the
+ four first uFrames */
- if (qh->period >= 8)
- period = qh->period/8;
- else
- period = qh->period;
-
- if (period >= 32)
- period = 16;
-
- if (qh->period >= 8) {
- /* millisecond period */
- period = (period << 3);
- } else {
- /* usof based tranmsfers */
- /* minimum 4 usofs */
- usof = 0x11;
- }
+ /*
+ * First 8 bits in dw5 is uSCS and "specifies which uSOF the
+ * complete split needs to be sent. Valid only for IN." Also,
+ * "All bits can be set to one for every transfer." (p 82,
+ * ISP1761 data sheet.) 0x1c is from Philips driver. Where did
+ * that number come from? 0xff seems to work fine...
+ */
+ /* ptd->dw5 = 0x1c; */
+ ptd->dw5 = 0xff; /* Execute Complete Split on any uFrame */
}
+ period = period >> 1;/* Ensure equal or shorter period than requested */
+ period &= 0xf8; /* Mask off too large values and lowest unused 3 bits */
+
ptd->dw2 |= period;
ptd->dw4 = usof;
}
@@ -1328,26 +1316,6 @@ static struct isp1760_qh *qh_make(struct usb_hcd *hcd, struct urb *urb,
is_input = usb_pipein(urb->pipe);
type = usb_pipetype(urb->pipe);
- if (type == PIPE_INTERRUPT) {
-
- if (urb->dev->speed == USB_SPEED_HIGH) {
-
- qh->period = urb->interval >> 3;
- if (qh->period == 0 && urb->interval != 1) {
- /* NOTE interval 2 or 4 uframes could work.
- * But interval 1 scheduling is simpler, and
- * includes high bandwidth.
- */
- dev_err(hcd->self.controller, "intr period %d uframes, NYET!",
- urb->interval);
- qh_destroy(qh);
- return NULL;
- }
- } else {
- qh->period = urb->interval;
- }
- }
-
if (!usb_pipecontrol(urb->pipe))
usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), !is_input,
1);