From: Hongyu Xie <xy521521@xxxxxxxxx> [ Upstream commit 808925075fb750804a60ff0710614466c396db4 ] irq is disabled in xhci_quiesce(called by xhci_halt, with bit:2 cleared in USBCMD register), but xhci_run(called by usb_add_hcd) re-enable it. It's possible that you will receive thousands of interrupt requests after initialization for 2.0 roothub. And you will get a lot of warning like, "xHCI dying, ignoring interrupt. Shouldn't IRQs be disabled?". This amount of interrupt requests will cause the entire system to freeze. This problem was first found on a device with ASM2142 host controller on it. [tidy up old code while moving it, reword header -Mathias] Cc: stable@xxxxxxxxxx Signed-off-by: Hongyu Xie <xiehongyu1@xxxxxxxxxx> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220623111945.1557702-2-mathias.nyman@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 5.15 Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx> --- drivers/usb/host/xhci.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 541fe4d..7ee747e 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -607,8 +607,27 @@ static int xhci_init(struct usb_hcd *hcd) static int xhci_run_finished(struct xhci_hcd *xhci) { + unsigned long flags; + u32 temp; + + /* + * Enable interrupts before starting the host (xhci 4.2 and 5.5.2). + * Protect the short window before host is running with a lock + */ + spin_lock_irqsave(&xhci->lock, flags); + + xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Enable interrupts"); + temp = readl(&xhci->op_regs->command); + temp |= (CMD_EIE); + writel(temp, &xhci->op_regs->command); + + xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Enable primary interrupter"); + temp = readl(&xhci->ir_set->irq_pending); + writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending); + if (xhci_start(xhci)) { xhci_halt(xhci); + spin_unlock_irqrestore(&xhci->lock, flags); return -ENODEV; } xhci->shared_hcd->state = HC_STATE_RUNNING; @@ -619,6 +638,8 @@ static int xhci_run_finished(struct xhci_hcd *xhci) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Finished xhci_run for USB3 roothub"); + + spin_unlock_irqrestore(&xhci->lock, flags); return 0; } @@ -667,19 +688,6 @@ int xhci_run(struct usb_hcd *hcd) temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK; writel(temp, &xhci->ir_set->irq_control); - /* Set the HCD state before we enable the irqs */ - temp = readl(&xhci->op_regs->command); - temp |= (CMD_EIE); - xhci_dbg_trace(xhci, trace_xhci_dbg_init, - "// Enable interrupts, cmd = 0x%x.", temp); - writel(temp, &xhci->op_regs->command); - - temp = readl(&xhci->ir_set->irq_pending); - xhci_dbg_trace(xhci, trace_xhci_dbg_init, - "// Enabling event ring interrupter %p by writing 0x%x to irq_pending", - xhci->ir_set, (unsigned int) ER_IRQ_ENABLE(temp)); - writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending); - if (xhci->quirks & XHCI_NEC_HOST) { struct xhci_command *command; -- 2.7.4
