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Commit a44f0d73 authored by Hemant Kumar's avatar Hemant Kumar
Browse files

usb: xhci: Clear event handler busy flag upon event ring cleanup 



There is a possibility of unacknowledged pending interrupt at the time
of secondary event ring cleanup. As a result xHC does not generate any
interrupt further because event handler busy flag is set. Hence disable
interrupter to prevent any further interrupt, acknowledge any pending
interrupt and clear event handler busy flag. This allows xHC to generate
interrupt after setting up new event ring.

Change-Id: I1b1791eacbf7afffd101d56d0ae06fe237b8c076
Signed-off-by: default avatarHemant Kumar <hemantk@codeaurora.org>
parent 787b74a4

drivers/usb/host/xhci-mem.c

+28 −2
Original line number Diff line number Diff line
@@ -1834,6 +1834,8 @@ void xhci_free_erst(struct xhci_hcd *xhci, struct xhci_erst *erst) 
int xhci_sec_event_ring_cleanup(struct usb_hcd *hcd, unsigned int intr_num)

{

	int size;

	u32 iman_reg;

	u64 erdp_reg;

	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	struct device	*dev = xhci_to_hcd(xhci)->self.sysdev;
@@ -1845,14 +1847,38 @@ int xhci_sec_event_ring_cleanup(struct usb_hcd *hcd, unsigned int intr_num) 


	size =

	sizeof(struct xhci_erst_entry)*(xhci->sec_erst[intr_num].num_entries);

	if (xhci->sec_erst[intr_num].entries)

	if (xhci->sec_erst[intr_num].entries) {

		/*

		 * disable irq, ack pending interrupt and clear EHB for xHC to

		 * generate interrupt again when new event ring is setup

		 */

		iman_reg =

			readl_relaxed(&xhci->sec_ir_set[intr_num]->irq_pending);

		iman_reg &= ~IMAN_IE;

		writel_relaxed(iman_reg,

				&xhci->sec_ir_set[intr_num]->irq_pending);

		iman_reg =

			readl_relaxed(&xhci->sec_ir_set[intr_num]->irq_pending);

		if (iman_reg & IMAN_IP)

			writel_relaxed(iman_reg,

				&xhci->sec_ir_set[intr_num]->irq_pending);

		/* make sure IP gets cleared before clearing EHB */

		mb();



		erdp_reg = xhci_read_64(xhci,

				&xhci->sec_ir_set[intr_num]->erst_dequeue);

		xhci_write_64(xhci, erdp_reg | ERST_EHB,

				&xhci->sec_ir_set[intr_num]->erst_dequeue);



		dma_free_coherent(dev, size, xhci->sec_erst[intr_num].entries,

				xhci->sec_erst[intr_num].erst_dma_addr);

		xhci->sec_erst[intr_num].entries = NULL;

	}

	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Freed SEC ERST#%d",

		intr_num);

	if (xhci->sec_event_ring[intr_num])

		xhci_ring_free(xhci, xhci->sec_event_ring[intr_num]);



	xhci->sec_event_ring[intr_num] = NULL;

	xhci_dbg_trace(xhci, trace_xhci_dbg_init,

		"Freed sec event ring");