Commit 01d940ff authored Mar 17, 2017 by Hemant Kumar Committed by Gerrit - the friendly Code Review server Sep 13, 2018

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 <hemantk@codeaurora.org>

parent d635f485

drivers/usb/host/xhci.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -119,7 +119,13 @@ 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.",
		@@ -140,6 +146,8 @@ 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;
		}