From 517f1673b8661e5bdbba3acebc8d1c66c3e44679 Mon Sep 17 00:00:00 2001 From: Hemant Kumar Date: Fri, 17 Mar 2017 14:02:00 -0700 Subject: [PATCH] usb: core: Enable xhci irq after starting controller There is a possibility of port change event triggering xhci irq as soon as halt bit is cleared in xhci_start(). As a result before xhci state is changed from XHCI_STATE_HALTED to 0 port change event keeps on generated until port status is acknowledged. This does not allow xhci_start() to finish and handle the port change event if irq is keep on getting fired on same core where xhci_start() is running. Fix this issue by disabling irq before starting controller and enable it back after clearing halt bit. Change-Id: I798620f99a7ba522258455642e6e8091ebf2cd34 Signed-off-by: Hemant Kumar --- drivers/usb/host/xhci.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 6c17e3fe181a..8081fee0e45d 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -132,7 +132,13 @@ int xhci_start(struct xhci_hcd *xhci) { u32 temp; int ret; + struct usb_hcd *hcd = xhci_to_hcd(xhci); + /* + * disable irq to avoid xhci_irq flooding due to unhandeled port + * change event in halt state, as soon as xhci_start clears halt bit + */ + disable_irq(hcd->irq); temp = readl(&xhci->op_regs->command); temp |= (CMD_RUN); xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Turn on HC, cmd = 0x%x.", @@ -153,6 +159,8 @@ int xhci_start(struct xhci_hcd *xhci) /* clear state flags. Including dying, halted or removing */ xhci->xhc_state = 0; + enable_irq(hcd->irq); + return ret; }