From a54f59199a81faec807e23fa265ba8f5e9f725a7 Mon Sep 17 00:00:00 2001 From: William Wu Date: Fri, 11 May 2018 17:46:32 +0800 Subject: [PATCH] usb: dwc2: fix isoc split in transfer with no data [ Upstream commit 70c3c8cb83856758025c2a211dd022bc0478922a ] If isoc split in transfer with no data (the length of DATA0 packet is zero), we can't simply return immediately. Because the DATA0 can be the first transaction or the second transaction for the isoc split in transaction. If the DATA0 packet with no data is in the first transaction, we can return immediately. But if the DATA0 packet with no data is in the second transaction of isoc split in transaction sequence, we need to increase the qtd->isoc_frame_index and giveback urb to device driver if needed, otherwise, the MDATA packet will be lost. A typical test case is that connect the dwc2 controller with an usb hs Hub (GL852G-12), and plug an usb fs audio device (Plantronics headset) into the downstream port of Hub. Then use the usb mic to record, we can find noise when playback. In the case, the isoc split in transaction sequence like this: - SSPLIT IN transaction - CSPLIT IN transaction - MDATA packet (176 bytes) - CSPLIT IN transaction - DATA0 packet (0 byte) This patch use both the length of DATA0 and qtd->isoc_split_offset to check if the DATA0 is in the second transaction. Tested-by: Gevorg Sahakyan Tested-by: Heiko Stuebner Acked-by: Minas Harutyunyan hminas@synopsys.com> Signed-off-by: William Wu Signed-off-by: Felipe Balbi Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc2/hcd_intr.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c index 5f72140..17905ba 100644 --- a/drivers/usb/dwc2/hcd_intr.c +++ b/drivers/usb/dwc2/hcd_intr.c @@ -923,9 +923,8 @@ static int dwc2_xfercomp_isoc_split_in(struct dwc2_hsotg *hsotg, frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index]; len = dwc2_get_actual_xfer_length(hsotg, chan, chnum, qtd, DWC2_HC_XFER_COMPLETE, NULL); - if (!len) { + if (!len && !qtd->isoc_split_offset) { qtd->complete_split = 0; - qtd->isoc_split_offset = 0; return 0; } -- 2.7.4