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@xxxxxxxxx>
> >
> > 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>
> > ---
> > 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@xxxxxxxxxxxxxxx> # 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>
