[PATCH 0/4] xhci fixes for usb-linus

[PATCH 0/4] xhci fixes for usb-linus

[Mathias Nyman]

Hi Greg

A few xhci fixes for 5.19
Adding a couple PCI IDs, turning off port power in shutdown, and delay
xHC interrupt generation until host is running.

Thanks
Mathias

Hongyu Xie (1):
  xhci: Keep interrupt disabled in initialization until host is running.

Mathias Nyman (1):
  xhci: turn off port power in shutdown

Tanveer Alam (1):
  xhci-pci: Allow host runtime PM as default for Intel Raptor Lake xHCI

Utkarsh Patel (1):
  xhci-pci: Allow host runtime PM as default for Intel Meteor Lake xHCI

 drivers/usb/host/xhci-hub.c |  2 +-
 drivers/usb/host/xhci-pci.c |  6 ++++-
 drivers/usb/host/xhci.c     | 50 ++++++++++++++++++++++++++-----------
 drivers/usb/host/xhci.h     |  2 ++
 4 files changed, 43 insertions(+), 17 deletions(-)

-- 
2.25.1

[PATCH 1/4] xhci: Keep interrupt disabled in initialization until host is running.

[Mathias Nyman]

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;
 
-- 
2.25.1

[PATCH 2/4] xhci: turn off port power in shutdown

[Mathias Nyman]

If ports are not turned off in shutdown then runtime suspended
self-powered USB devices may survive in U3 link state over S5.

During subsequent boot, if firmware sends an IPC command to program
the port in DISCONNECT state, it will time out, causing significant
delay in the boot time.

Turning off roothub port power is also recommended in xhci
specification 4.19.4 "Port Power" in the additional note.

Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-hub.c |  2 +-
 drivers/usb/host/xhci.c     | 15 +++++++++++++--
 drivers/usb/host/xhci.h     |  2 ++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index c54f2bc23d3f..0fdc014c9401 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -652,7 +652,7 @@ struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd)
  * It will release and re-aquire the lock while calling ACPI
  * method.
  */
-static void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
+void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
 				u16 index, bool on, unsigned long *flags)
 	__must_hold(&xhci->lock)
 {
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index cb99bed5f755..65858f607437 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -791,6 +791,8 @@ static void xhci_stop(struct usb_hcd *hcd)
 void xhci_shutdown(struct usb_hcd *hcd)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	unsigned long flags;
+	int i;
 
 	if (xhci->quirks & XHCI_SPURIOUS_REBOOT)
 		usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev));
@@ -806,12 +808,21 @@ void xhci_shutdown(struct usb_hcd *hcd)
 		del_timer_sync(&xhci->shared_hcd->rh_timer);
 	}
 
-	spin_lock_irq(&xhci->lock);
+	spin_lock_irqsave(&xhci->lock, flags);
 	xhci_halt(xhci);
+
+	/* Power off USB2 ports*/
+	for (i = 0; i < xhci->usb2_rhub.num_ports; i++)
+		xhci_set_port_power(xhci, xhci->main_hcd, i, false, &flags);
+
+	/* Power off USB3 ports*/
+	for (i = 0; i < xhci->usb3_rhub.num_ports; i++)
+		xhci_set_port_power(xhci, xhci->shared_hcd, i, false, &flags);
+
 	/* Workaround for spurious wakeups at shutdown with HSW */
 	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
 		xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
-	spin_unlock_irq(&xhci->lock);
+	spin_unlock_irqrestore(&xhci->lock, flags);
 
 	xhci_cleanup_msix(xhci);
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 0bd76c94a4b1..28aaf031f9a8 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2196,6 +2196,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
 int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);
 int xhci_find_raw_port_number(struct usb_hcd *hcd, int port1);
 struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd);
+void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd, u16 index,
+			 bool on, unsigned long *flags);
 
 void xhci_hc_died(struct xhci_hcd *xhci);
 
-- 
2.25.1

[PATCH 3/4] xhci-pci: Allow host runtime PM as default for Intel Raptor Lake xHCI

[Mathias Nyman]

From: Tanveer Alam <tanveer1.alam@intel.com>

In the same way as Intel Alder Lake TCSS (Type-C Subsystem) the Raptor
Lake TCSS xHCI needs to be runtime suspended whenever possible to
allow the TCSS hardware block to enter D3cold and thus save energy.

Cc: stable@kernel.org
Signed-off-by: Tanveer Alam <tanveer1.alam@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-pci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index fac9492a8bda..d66ea276ccec 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -61,6 +61,7 @@
 #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_XHCI		0x461e
 #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_XHCI		0x464e
 #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI	0x51ed
+#define PCI_DEVICE_ID_INTEL_RAPTOR_LAKE_XHCI		0xa71e
 
 #define PCI_DEVICE_ID_AMD_RENOIR_XHCI			0x1639
 #define PCI_DEVICE_ID_AMD_PROMONTORYA_4			0x43b9
@@ -269,7 +270,8 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == PCI_DEVICE_ID_INTEL_MAPLE_RIDGE_XHCI ||
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_XHCI ||
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_XHCI ||
-	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI))
+	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI ||
+	     pdev->device == PCI_DEVICE_ID_INTEL_RAPTOR_LAKE_XHCI))
 		xhci->quirks |= XHCI_DEFAULT_PM_RUNTIME_ALLOW;
 
 	if (pdev->vendor == PCI_VENDOR_ID_ETRON &&
-- 
2.25.1

[PATCH 4/4] xhci-pci: Allow host runtime PM as default for Intel Meteor Lake xHCI

[Mathias Nyman]

From: Utkarsh Patel <utkarsh.h.patel@intel.com>

Meteor Lake TCSS(Type-C Subsystem) xHCI needs to be runtime suspended
whenever possible to allow the TCSS hardware block to enter D3cold and
thus save energy.

Cc: stable@kernel.org
Signed-off-by: Utkarsh Patel <utkarsh.h.patel@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-pci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index d66ea276ccec..dce6c0ec8d34 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -62,6 +62,7 @@
 #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_XHCI		0x464e
 #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI	0x51ed
 #define PCI_DEVICE_ID_INTEL_RAPTOR_LAKE_XHCI		0xa71e
+#define PCI_DEVICE_ID_INTEL_METEOR_LAKE_XHCI		0x7ec0
 
 #define PCI_DEVICE_ID_AMD_RENOIR_XHCI			0x1639
 #define PCI_DEVICE_ID_AMD_PROMONTORYA_4			0x43b9
@@ -271,7 +272,8 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_XHCI ||
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_XHCI ||
 	     pdev->device == PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI ||
-	     pdev->device == PCI_DEVICE_ID_INTEL_RAPTOR_LAKE_XHCI))
+	     pdev->device == PCI_DEVICE_ID_INTEL_RAPTOR_LAKE_XHCI ||
+	     pdev->device == PCI_DEVICE_ID_INTEL_METEOR_LAKE_XHCI))
 		xhci->quirks |= XHCI_DEFAULT_PM_RUNTIME_ALLOW;
 
 	if (pdev->vendor == PCI_VENDOR_ID_ETRON &&
-- 
2.25.1

Re: [PATCH 2/4] xhci: turn off port power in shutdown

[Joey Corleone]

On 23.06.22 13:19, Mathias Nyman wrote:
> If ports are not turned off in shutdown then runtime suspended
> self-powered USB devices may survive in U3 link state over S5.
> 
> During subsequent boot, if firmware sends an IPC command to program
> the port in DISCONNECT state, it will time out, causing significant
> delay in the boot time.
> 
> Turning off roothub port power is also recommended in xhci
> specification 4.19.4 "Port Power" in the additional note.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
>   drivers/usb/host/xhci-hub.c |  2 +-
>   drivers/usb/host/xhci.c     | 15 +++++++++++++--
>   drivers/usb/host/xhci.h     |  2 ++
>   3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index c54f2bc23d3f..0fdc014c9401 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -652,7 +652,7 @@ struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd)
>    * It will release and re-aquire the lock while calling ACPI
>    * method.
>    */
> -static void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
> +void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
>   				u16 index, bool on, unsigned long *flags)
>   	__must_hold(&xhci->lock)
>   {
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index cb99bed5f755..65858f607437 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -791,6 +791,8 @@ static void xhci_stop(struct usb_hcd *hcd)
>   void xhci_shutdown(struct usb_hcd *hcd)
>   {
>   	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +	unsigned long flags;
> +	int i;
>   
>   	if (xhci->quirks & XHCI_SPURIOUS_REBOOT)
>   		usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev));
> @@ -806,12 +808,21 @@ void xhci_shutdown(struct usb_hcd *hcd)
>   		del_timer_sync(&xhci->shared_hcd->rh_timer);
>   	}
>   
> -	spin_lock_irq(&xhci->lock);
> +	spin_lock_irqsave(&xhci->lock, flags);
>   	xhci_halt(xhci);
> +
> +	/* Power off USB2 ports*/
> +	for (i = 0; i < xhci->usb2_rhub.num_ports; i++)
> +		xhci_set_port_power(xhci, xhci->main_hcd, i, false, &flags);
> +
> +	/* Power off USB3 ports*/
> +	for (i = 0; i < xhci->usb3_rhub.num_ports; i++)
> +		xhci_set_port_power(xhci, xhci->shared_hcd, i, false, &flags);
> +
>   	/* Workaround for spurious wakeups at shutdown with HSW */
>   	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
>   		xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
> -	spin_unlock_irq(&xhci->lock);
> +	spin_unlock_irqrestore(&xhci->lock, flags);
>   
>   	xhci_cleanup_msix(xhci);
>   
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 0bd76c94a4b1..28aaf031f9a8 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -2196,6 +2196,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
>   int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);
>   int xhci_find_raw_port_number(struct usb_hcd *hcd, int port1);
>   struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd);
> +void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd, u16 index,
> +			 bool on, unsigned long *flags);
>   
>   void xhci_hc_died(struct xhci_hcd *xhci);
>   

fyi: there is a report [1] about a regression introduced by this patch.

Joey

[1] https://bugzilla.kernel.org/show_bug.cgi?id=216243

Re: [PATCH 2/4] xhci: turn off port power in shutdown

[Mathias Nyman]

On 19.7.2022 16.42, Joey Corleone wrote:
> On 23.06.22 13:19, Mathias Nyman wrote:
>> If ports are not turned off in shutdown then runtime suspended
>> self-powered USB devices may survive in U3 link state over S5.
>>
>> During subsequent boot, if firmware sends an IPC command to program
>> the port in DISCONNECT state, it will time out, causing significant
>> delay in the boot time.
>>
>> Turning off roothub port power is also recommended in xhci
>> specification 4.19.4 "Port Power" in the additional note.
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
>> ---
>>   drivers/usb/host/xhci-hub.c |  2 +-
>>   drivers/usb/host/xhci.c     | 15 +++++++++++++--
>>   drivers/usb/host/xhci.h     |  2 ++
>>   3 files changed, 16 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
>> index c54f2bc23d3f..0fdc014c9401 100644
>> --- a/drivers/usb/host/xhci-hub.c
>> +++ b/drivers/usb/host/xhci-hub.c
>> @@ -652,7 +652,7 @@ struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd)
>>    * It will release and re-aquire the lock while calling ACPI
>>    * method.
>>    */
>> -static void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
>> +void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
>>                   u16 index, bool on, unsigned long *flags)
>>       __must_hold(&xhci->lock)
>>   {
>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index cb99bed5f755..65858f607437 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -791,6 +791,8 @@ static void xhci_stop(struct usb_hcd *hcd)
>>   void xhci_shutdown(struct usb_hcd *hcd)
>>   {
>>       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>> +    unsigned long flags;
>> +    int i;
>>       if (xhci->quirks & XHCI_SPURIOUS_REBOOT)
>>           usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev));
>> @@ -806,12 +808,21 @@ void xhci_shutdown(struct usb_hcd *hcd)
>>           del_timer_sync(&xhci->shared_hcd->rh_timer);
>>       }
>> -    spin_lock_irq(&xhci->lock);
>> +    spin_lock_irqsave(&xhci->lock, flags);
>>       xhci_halt(xhci);
>> +
>> +    /* Power off USB2 ports*/
>> +    for (i = 0; i < xhci->usb2_rhub.num_ports; i++)
>> +        xhci_set_port_power(xhci, xhci->main_hcd, i, false, &flags);
>> +
>> +    /* Power off USB3 ports*/
>> +    for (i = 0; i < xhci->usb3_rhub.num_ports; i++)
>> +        xhci_set_port_power(xhci, xhci->shared_hcd, i, false, &flags);
>> +
>>       /* Workaround for spurious wakeups at shutdown with HSW */
>>       if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
>>           xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
>> -    spin_unlock_irq(&xhci->lock);
>> +    spin_unlock_irqrestore(&xhci->lock, flags);
>>       xhci_cleanup_msix(xhci);
>> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
>> index 0bd76c94a4b1..28aaf031f9a8 100644
>> --- a/drivers/usb/host/xhci.h
>> +++ b/drivers/usb/host/xhci.h
>> @@ -2196,6 +2196,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
>>   int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);
>>   int xhci_find_raw_port_number(struct usb_hcd *hcd, int port1);
>>   struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd);
>> +void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd, u16 index,
>> +             bool on, unsigned long *flags);
>>   void xhci_hc_died(struct xhci_hcd *xhci);
> 
> fyi: there is a report [1] about a regression introduced by this patch.
> 
> Joey
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=216243

Thanks for the notice, I'm away until August.
If it starts to cause more issues then this one incident then it should be reverted.

Will take a look at this when I return.
Meanwhile a log with xhci dynamic debug enabled could better show what is going on

mount -t debugfs none /sys/kernel/debug
echo 'module xhci_hcd =p' >/sys/kernel/debug/dynamic_debug/control

Thanks
Mathias

Re: [PATCH 1/4] xhci: Keep interrupt disabled in initialization until host is running.

[Prashanth K]

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

Thanks,
Prashanth K

Re: [PATCH 1/4] xhci: Keep interrupt disabled in initialization until host is running.

[Greg KH]

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>