On Wed, Sep 13, 2023 at 11:30:41AM +0530, Prashanth K wrote:

On 23-06-22 04:49 pm, Mathias Nyman wrote:

...

From: Hongyu Xie xy521521@gmail.com

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

---

drivers/usb/host/xhci.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-)

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;

This is not available to older kernels [< 5.19]. Can we get this backported to 5.15 as well? Please let me know if there is some other way to do it.

Cc: stable@vger.kernel.org # 5.15

<formletter>

This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.

</formletter>