On Wed, Aug 28, 2013 at 12:24 PM, Ming Lei <tom.leiming@xxxxxxxxx> wrote:
> On Wed, 28 Aug 2013 12:02:03 +0800
> Ming Lei <ming.lei@xxxxxxxxxxxxx> wrote:
>
>> Actually the problem only happened when underrun without
>> URB_ISO_ASAP.
>>
>> I have another fix which uses rebase trick and is simper(less change), could
>> you comment on the attachment patch?
>
> Sorry, please ignore last attachment patch, and comment on the below one:
>
> diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
> index 83be03f..4a3ddc9 100644
> --- a/drivers/usb/host/ehci-sched.c
> +++ b/drivers/usb/host/ehci-sched.c
> @@ -1370,6 +1370,21 @@ sitd_slot_ok (
> return 1;
> }
>
> +/* rebase in case of underun without ISO_ASAP together */
> +static void iso_stream_rebase(struct ehci_hcd *ehci,
> + struct ehci_iso_stream *stream, u32 mod)
> +{
> + u32 i;
> +
> + if (ehci->last_base == -1)
> + return;
> +
> + for (i = ehci->last_base; i != ehci->last_iso_frame;
> + i = (i + 1) & (mod - 1))
> + if ((stream->next_uframe & (mod - 1)) == i)
> + ehci->last_iso_frame = i;
> +}
mod should switch to ehci->periodic_size, and stream->next_uframe
should convert to frame.
Also if the URB has been completed('now' is behind 'start + span'), the URB
need to complete immediately, or rescan after linking simply.
I will prepare for another one later.
> +
> /*
> * This scheduler plans almost as far into the future as it has actual
> * periodic schedule slots. (Affected by TUNE_FLS, which defaults to
> @@ -1409,7 +1424,9 @@ iso_stream_schedule (
> * (irq delays etc). If there are, the behavior depends on
> * whether URB_ISO_ASAP is set.
> */
> - if (likely (!list_empty (&stream->td_list))) {
> + if (likely (!list_empty (&stream->td_list) ||
> + hcd_complete_in_progress(
> + ehci_to_hcd(ehci), urb))) {
>
> /* Take the isochronous scheduling threshold into account */
> if (ehci->i_thresh)
> @@ -1417,6 +1434,10 @@ iso_stream_schedule (
> else
> next = (now + 2 + 7) & ~0x07; /* full frame cache */
>
> + if (list_empty(&stream->td_list) &&
> + !(urb->transfer_flags & URB_ISO_ASAP))
> + iso_stream_rebase(ehci, stream, mod);
> +
> /*
> * Use ehci->last_iso_frame as the base. There can't be any
> * TDs scheduled for earlier than that.
> @@ -1517,6 +1538,7 @@ iso_stream_schedule (
> /* Make sure scan_isoc() sees these */
> if (ehci->isoc_count == 0)
> ehci->last_iso_frame = now >> 3;
> + ehci->last_base = -1;
> return 0;
>
> fail:
> @@ -2255,6 +2277,9 @@ static void scan_isoc(struct ehci_hcd *ehci)
> }
> ehci->now_frame = now_frame;
>
> + if (ehci->last_base == -1)
> + ehci->last_base = ehci->last_iso_frame;
> +
> frame = ehci->last_iso_frame;
> for (;;) {
> union ehci_shadow q, *q_p;
>
>
Thanks,
--
Ming Lei
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