From c17b337c1ea4c681595531912585a94f4bd7f8e7 Mon Sep 17 00:00:00 2001 From: Gregory Herrero Date: Thu, 5 Nov 2015 09:41:43 +0100 Subject: [PATCH] usb: dwc2: host: program descriptor for next frame Isochronous descriptor is currently programmed for the frame after the last descriptor was programmed. If the last descriptor frame underrun, then current descriptor must take this into account and must be programmed on the current frame + 1. This overrun usually happens when system is loaded and dwc2 can't init descriptor list in time. Acked-by: John Youn Signed-off-by: Gregory Herrero Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/hcd.h | 2 ++ drivers/usb/dwc2/hcd_ddma.c | 32 ++++++++++++++++++++++++++++++-- 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc2/hcd.h b/drivers/usb/dwc2/hcd.h index a19837f655c9..2e5e9d9a0016 100644 --- a/drivers/usb/dwc2/hcd.h +++ b/drivers/usb/dwc2/hcd.h @@ -340,6 +340,8 @@ struct dwc2_qtd { u8 isoc_split_pos; u16 isoc_frame_index; u16 isoc_split_offset; + u16 isoc_td_last; + u16 isoc_td_first; u32 ssplit_out_xfer_count; u8 error_count; u8 n_desc; diff --git a/drivers/usb/dwc2/hcd_ddma.c b/drivers/usb/dwc2/hcd_ddma.c index a76a58c35fea..9635d8d4bba4 100644 --- a/drivers/usb/dwc2/hcd_ddma.c +++ b/drivers/usb/dwc2/hcd_ddma.c @@ -547,11 +547,32 @@ static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg, { struct dwc2_qtd *qtd; u32 max_xfer_size; - u16 idx, inc, n_desc, ntd_max = 0; + u16 idx, inc, n_desc = 0, ntd_max = 0; + u16 cur_idx; + u16 next_idx; idx = qh->td_last; inc = qh->interval; - n_desc = 0; + hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg); + cur_idx = dwc2_frame_list_idx(hsotg->frame_number); + next_idx = dwc2_desclist_idx_inc(qh->td_last, inc, qh->dev_speed); + + /* + * Ensure current frame number didn't overstep last scheduled + * descriptor. If it happens, the only way to recover is to move + * qh->td_last to current frame number + 1. + * So that next isoc descriptor will be scheduled on frame number + 1 + * and not on a past frame. + */ + if (dwc2_frame_idx_num_gt(cur_idx, next_idx) || (cur_idx == next_idx)) { + if (inc < 32) { + dev_vdbg(hsotg->dev, + "current frame number overstep last descriptor\n"); + qh->td_last = dwc2_desclist_idx_inc(cur_idx, inc, + qh->dev_speed); + idx = qh->td_last; + } + } if (qh->interval) { ntd_max = (dwc2_max_desc_num(qh) + qh->interval - 1) / @@ -564,6 +585,12 @@ static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg, MAX_ISOC_XFER_SIZE_HS : MAX_ISOC_XFER_SIZE_FS; list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) { + if (qtd->in_process && + qtd->isoc_frame_index_last == + qtd->urb->packet_count) + continue; + + qtd->isoc_td_first = idx; while (qh->ntd < ntd_max && qtd->isoc_frame_index_last < qtd->urb->packet_count) { dwc2_fill_host_isoc_dma_desc(hsotg, qtd, qh, @@ -571,6 +598,7 @@ static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg, idx = dwc2_desclist_idx_inc(idx, inc, qh->dev_speed); n_desc++; } + qtd->isoc_td_last = idx; qtd->in_process = 1; } -- 2.11.0