The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a808925075fb750804a60ff0710614466c396db4 Mon Sep 17 00:00:00 2001 From: Hongyu Xie xy521521@gmail.com Date: Thu, 23 Jun 2022 14:19:42 +0300 Subject: [PATCH] xhci: Keep interrupt disabled in initialization until host is running.
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@kernel.org Signed-off-by: Hongyu Xie xiehongyu1@kylinos.cn Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20220623111945.1557702-2-mathias.nyman@linux.intel... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 9ac56e9ffc64..cb99bed5f755 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -611,15 +611,37 @@ 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->cmd_ring_state = CMD_RING_STATE_RUNNING;
if (xhci->quirks & XHCI_NEC_HOST) xhci_ring_cmd_db(xhci);
+ spin_unlock_irqrestore(&xhci->lock, flags); + return 0; }
@@ -668,19 +690,6 @@ 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;