From 28632b44d129cd2dc677475197a01cced307cfc5 Mon Sep 17 00:00:00 2001 From: John Youn Date: Mon, 14 Nov 2016 12:32:45 -0800 Subject: [PATCH] usb: dwc3: Workaround for irq mask issue This is a workaround for STAR 9000961433 which affects only version 3.00a of the DWC_usb3 core. This prevents the controller interrupt from being masked while handling events. Enabling interrupt moderation allows us to work around this issue because once the GEVNTCOUNT.count is written the IRQ is immediately deasserted and won't be asserted again until GEVNTCOUNT.EHB is cleared. Signed-off-by: John Youn Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 889dbabc7c2d..e95144870210 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1004,6 +1004,17 @@ static void dwc3_check_params(struct dwc3 *dwc) dwc->imod_interval = 0; } + /* + * Workaround for STAR 9000961433 which affects only version + * 3.00a of the DWC_usb3 core. This prevents the controller + * interrupt from being masked while handling events. IMOD + * allows us to work around this issue. Enable it for the + * affected version. + */ + if (!dwc->imod_interval && + (dwc->revision == DWC3_REVISION_300A)) + dwc->imod_interval = 1; + /* Check the maximum_speed parameter */ switch (dwc->maximum_speed) { case USB_SPEED_LOW: