From d53701067f048b8b11635e964b6d3bd9a248c622 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 14 Aug 2018 10:42:43 +0300 Subject: [PATCH] usb: dwc3: gadget: check if dep->frame_number is still valid Gadget driver may take an unbounded amount of time to queue requests after XferNotReady. This is important for isochronous endpoints which need to be started for a specific (micro-)frame. If we fail to start a transfer for isochronous endpoint, let's try queueing to a future interval and see if that helps. We will stop trying if we fail a start transfer for 5 intervals in the future. Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/core.h | 1 + drivers/usb/dwc3/gadget.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 58f4aa5e3443..15c07b2b5866 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -37,6 +37,7 @@ #define DWC3_EP0_SETUP_SIZE 512 #define DWC3_ENDPOINTS_NUM 32 #define DWC3_XHCI_RESOURCES_NUM 2 +#define DWC3_ISOC_MAX_RETRIES 5 #define DWC3_SCRATCHBUF_SIZE 4096 /* each buffer is assumed to be 4KiB */ #define DWC3_EVENT_BUFFERS_SIZE 4096 diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index e94971a7f468..c4e91c6d4fce 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -27,7 +27,7 @@ #include "gadget.h" #include "io.h" -#define DWC3_ALIGN_FRAME(d) (((d)->frame_number + (d)->interval) \ +#define DWC3_ALIGN_FRAME(d, n) (((d)->frame_number + ((d)->interval * (n))) \ & ~((d)->interval - 1)) /** @@ -1384,6 +1384,8 @@ static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep) static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep) { struct dwc3 *dwc = dep->dwc; + int ret; + int i; if (list_empty(&dep->pending_list)) { dep->flags |= DWC3_EP_PENDING_REQUEST; @@ -1400,8 +1402,15 @@ static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep) return dwc3_gadget_start_isoc_quirk(dep); } - dep->frame_number = DWC3_ALIGN_FRAME(dep); - return __dwc3_gadget_kick_transfer(dep); + for (i = 0; i < DWC3_ISOC_MAX_RETRIES; i++) { + dep->frame_number = DWC3_ALIGN_FRAME(dep, i + 1); + + ret = __dwc3_gadget_kick_transfer(dep); + if (ret != -EAGAIN) + break; + } + + return ret; } static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)