diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2013-05-29 17:20:00 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-30 12:34:30 (GMT) |
| commit | 9db33f317432d1a9e22116092c6455ae71bf73fc (patch) | |
| tree | 955504b8b7659bf2a9c912d7add3b10da2e7e543 /drivers | |
| parent | 8a1ea51f87a6149c3263a63e9c60d852bedbecd7 (diff) | |
| download | linux-9db33f317432d1a9e22116092c6455ae71bf73fc.tar.xz | |
USB: IMX21: upgrade the isochronous API
This patch attempts to update the imx21-hcd driver to the current
standard for the isochronous API. Firstly, urb->start_frame should
always be set by the driver; it is not an input parameter. Secondly,
the URB_ISO_ASAP flag matters only when an URB is submitted to a
stream that has gotten an underrun. It causes the URB to be scheduled
for the next available slot in the future, rather than the earliest
unused (and expired) slot.
Unfortunately, I don't have any way to test these changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Martin Fuzzey <mfuzzey@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/imx21-hcd.c | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/drivers/usb/host/imx21-hcd.c b/drivers/usb/host/imx21-hcd.c index f0ebe8e..03dc4d9 100644 --- a/drivers/usb/host/imx21-hcd.c +++ b/drivers/usb/host/imx21-hcd.c @@ -809,26 +809,36 @@ static int imx21_hc_urb_enqueue_isoc(struct usb_hcd *hcd, /* calculate frame */ cur_frame = imx21_hc_get_frame(hcd); - if (urb->transfer_flags & URB_ISO_ASAP) { - if (list_empty(&ep_priv->td_list)) - urb->start_frame = cur_frame + 5; - else - urb->start_frame = list_entry( - ep_priv->td_list.prev, - struct td, list)->frame + urb->interval; - } - urb->start_frame = wrap_frame(urb->start_frame); - if (frame_after(cur_frame, urb->start_frame)) { - dev_dbg(imx21->dev, - "enqueue: adjusting iso start %d (cur=%d) asap=%d\n", - urb->start_frame, cur_frame, - (urb->transfer_flags & URB_ISO_ASAP) != 0); - urb->start_frame = wrap_frame(cur_frame + 1); + i = 0; + if (list_empty(&ep_priv->td_list)) { + urb->start_frame = wrap_frame(cur_frame + 5); + } else { + urb->start_frame = wrap_frame(list_entry(ep_priv->td_list.prev, + struct td, list)->frame + urb->interval); + + if (frame_after(cur_frame, urb->start_frame)) { + dev_dbg(imx21->dev, + "enqueue: adjusting iso start %d (cur=%d) asap=%d\n", + urb->start_frame, cur_frame, + (urb->transfer_flags & URB_ISO_ASAP) != 0); + i = DIV_ROUND_UP(wrap_frame( + cur_frame - urb->start_frame), + urb->interval); + if (urb->transfer_flags & URB_ISO_ASAP) { + urb->start_frame = wrap_frame(urb->start_frame + + i * urb->interval); + i = 0; + } else if (i >= urb->number_of_packets) { + ret = -EXDEV; + goto alloc_dmem_failed; + } + } } /* set up transfers */ + urb_priv->isoc_remaining = urb->number_of_packets - i; td = urb_priv->isoc_td; - for (i = 0; i < urb->number_of_packets; i++, td++) { + for (; i < urb->number_of_packets; i++, td++) { unsigned int offset = urb->iso_frame_desc[i].offset; td->ep = ep; td->urb = urb; @@ -840,7 +850,6 @@ static int imx21_hc_urb_enqueue_isoc(struct usb_hcd *hcd, list_add_tail(&td->list, &ep_priv->td_list); } - urb_priv->isoc_remaining = urb->number_of_packets; dev_vdbg(imx21->dev, "setup %d packets for iso frame %d->%d\n", urb->number_of_packets, urb->start_frame, td->frame); |