From 57911504a93909034ba5b90c20f3e6df8409ebd8 Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Fri, 6 Jul 2012 15:19:10 +0530 Subject: usb: dwc3: gadget: Fix dwc3_stop_active_transfer for synchronization delay dwc3_stop_active_transfer has been called from two places. After each calling of this function , we should allow 100 us delay to synchronize with interconnect. It would be better if we put this delay in that function only, rather than into calling routine of this function. Signed-off-by: Pratyush Anand Reported-by: Michel Sanches Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 43 ++++++++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 21 deletions(-) (limited to 'drivers/usb/dwc3') diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index fc059107c05..dd5945ca9c8 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -563,27 +563,7 @@ static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep) if (!list_empty(&dep->req_queued)) { dwc3_stop_active_transfer(dwc, dep->number); - /* - * NOTICE: We are violating what the Databook says about the - * EndTransfer command. Ideally we would _always_ wait for the - * EndTransfer Command Completion IRQ, but that's causing too - * much trouble synchronizing between us and gadget driver. - * - * We have discussed this with the IP Provider and it was - * suggested to giveback all requests here, but give HW some - * extra time to synchronize with the interconnect. We're using - * an arbitraty 100us delay for that. - * - * Note also that a similar handling was tested by Synopsys - * (thanks a lot Paul) and nothing bad has come out of it. - * In short, what we're doing is: - * - * - Issue EndTransfer WITH CMDIOC bit set - * - Wait 100us - * - giveback all requests to gadget driver - */ - udelay(100); - + /* - giveback all requests to gadget driver */ while (!list_empty(&dep->req_queued)) { req = next_request(&dep->req_queued); @@ -1875,6 +1855,25 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum) if (!dep->resource_index) return; + /* + * NOTICE: We are violating what the Databook says about the + * EndTransfer command. Ideally we would _always_ wait for the + * EndTransfer Command Completion IRQ, but that's causing too + * much trouble synchronizing between us and gadget driver. + * + * We have discussed this with the IP Provider and it was + * suggested to giveback all requests here, but give HW some + * extra time to synchronize with the interconnect. We're using + * an arbitraty 100us delay for that. + * + * Note also that a similar handling was tested by Synopsys + * (thanks a lot Paul) and nothing bad has come out of it. + * In short, what we're doing is: + * + * - Issue EndTransfer WITH CMDIOC bit set + * - Wait 100us + */ + cmd = DWC3_DEPCMD_ENDTRANSFER; cmd |= DWC3_DEPCMD_HIPRI_FORCERM | DWC3_DEPCMD_CMDIOC; cmd |= DWC3_DEPCMD_PARAM(dep->resource_index); @@ -1882,6 +1881,8 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum) ret = dwc3_send_gadget_ep_cmd(dwc, dep->number, cmd, ¶ms); WARN_ON_ONCE(ret); dep->resource_index = 0; + + udelay(100); } static void dwc3_stop_active_transfers(struct dwc3 *dwc) -- cgit v1.2.3