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authorHongyu Xie <xy521521@gmail.com>2022-06-23 14:19:42 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-06-23 17:27:28 +0300
commita808925075fb750804a60ff0710614466c396db4 (patch)
treee2caba5ca7576c8a76c00827c298888e9547e007 /drivers/usb/host
parent2bdc2bcd9a759613d6340c4a0b7f5d3b7a1a71a2 (diff)
downloadlinux-a808925075fb750804a60ff0710614466c396db4.tar.xz
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.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host')
-rw-r--r--drivers/usb/host/xhci.c35
1 files 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;