diff options
author | Alan Stern <stern@rowland.harvard.edu> | 2012-10-01 10:32:15 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-22 14:10:24 -0400 |
commit | 6a41b4d3fe8cd4cc95181516fc6fba7b1747a27c (patch) | |
tree | 2b4dc08f94a67985f595d157c399774cee4e661a /drivers | |
parent | c44b225077bb1fb25ed5cd5c4f226897b91bedd4 (diff) |
OHCI: implement new semantics for URB_ISO_ASAP
This patch (as1614) updates the isochronous scheduling in ohci-hcd to
match the new semantics for URB_ISO_ASAP. Testing revealed a hardware
bug in the way my OHCI controller handles expired isochronous TDs;
consequently the patch tries hard to avoid creating them (unlike the
ehci-hcd and uhci-hcd drivers).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/host/ohci-hcd.c | 36 | ||||
-rw-r--r-- | drivers/usb/host/ohci-q.c | 4 |
2 files changed, 34 insertions, 6 deletions
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index 4a1d64d92338..cfc1da30667c 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c | |||
@@ -231,13 +231,41 @@ static int ohci_urb_enqueue ( | |||
231 | frame &= ~(ed->interval - 1); | 231 | frame &= ~(ed->interval - 1); |
232 | frame |= ed->branch; | 232 | frame |= ed->branch; |
233 | urb->start_frame = frame; | 233 | urb->start_frame = frame; |
234 | } | ||
235 | } else if (ed->type == PIPE_ISOCHRONOUS) { | ||
236 | u16 next = ohci_frame_no(ohci) + 2; | ||
237 | u16 frame = ed->last_iso + ed->interval; | ||
238 | |||
239 | /* Behind the scheduling threshold? */ | ||
240 | if (unlikely(tick_before(frame, next))) { | ||
234 | 241 | ||
235 | /* yes, only URB_ISO_ASAP is supported, and | 242 | /* USB_ISO_ASAP: Round up to the first available slot */ |
236 | * urb->start_frame is never used as input. | 243 | if (urb->transfer_flags & URB_ISO_ASAP) |
244 | frame += (next - frame + ed->interval - 1) & | ||
245 | -ed->interval; | ||
246 | |||
247 | /* | ||
248 | * Not ASAP: Use the next slot in the stream. If | ||
249 | * the entire URB falls before the threshold, fail. | ||
237 | */ | 250 | */ |
251 | else if (tick_before(frame + ed->interval * | ||
252 | (urb->number_of_packets - 1), next)) { | ||
253 | retval = -EXDEV; | ||
254 | usb_hcd_unlink_urb_from_ep(hcd, urb); | ||
255 | goto fail; | ||
256 | } | ||
257 | |||
258 | /* | ||
259 | * Some OHCI hardware doesn't handle late TDs | ||
260 | * correctly. After retiring them it proceeds to | ||
261 | * the next ED instead of the next TD. Therefore | ||
262 | * we have to omit the late TDs entirely. | ||
263 | */ | ||
264 | urb_priv->td_cnt = DIV_ROUND_UP(next - frame, | ||
265 | ed->interval); | ||
238 | } | 266 | } |
239 | } else if (ed->type == PIPE_ISOCHRONOUS) | 267 | urb->start_frame = frame; |
240 | urb->start_frame = ed->last_iso + ed->interval; | 268 | } |
241 | 269 | ||
242 | /* fill the TDs and link them to the ed; and | 270 | /* fill the TDs and link them to the ed; and |
243 | * enable that part of the schedule, if needed | 271 | * enable that part of the schedule, if needed |
diff --git a/drivers/usb/host/ohci-q.c b/drivers/usb/host/ohci-q.c index c5a1ea9145fa..177a213790d4 100644 --- a/drivers/usb/host/ohci-q.c +++ b/drivers/usb/host/ohci-q.c | |||
@@ -596,7 +596,6 @@ static void td_submit_urb ( | |||
596 | urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C); | 596 | urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C); |
597 | } | 597 | } |
598 | 598 | ||
599 | urb_priv->td_cnt = 0; | ||
600 | list_add (&urb_priv->pending, &ohci->pending); | 599 | list_add (&urb_priv->pending, &ohci->pending); |
601 | 600 | ||
602 | if (data_len) | 601 | if (data_len) |
@@ -672,7 +671,8 @@ static void td_submit_urb ( | |||
672 | * we could often reduce the number of TDs here. | 671 | * we could often reduce the number of TDs here. |
673 | */ | 672 | */ |
674 | case PIPE_ISOCHRONOUS: | 673 | case PIPE_ISOCHRONOUS: |
675 | for (cnt = 0; cnt < urb->number_of_packets; cnt++) { | 674 | for (cnt = urb_priv->td_cnt; cnt < urb->number_of_packets; |
675 | cnt++) { | ||
676 | int frame = urb->start_frame; | 676 | int frame = urb->start_frame; |
677 | 677 | ||
678 | // FIXME scheduling should handle frame counter | 678 | // FIXME scheduling should handle frame counter |