usb/core: skip unnecessary line IRQ request for USB3

PATCH In review Alex Shi 3 participants 6 messages Mar 15, 2012 – Mar 16, 2012

Subsystems (2)

USB USB xHCI driver

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Alex Shi

author

2012-03-15 04:48 UTC #0 lore raw

PATCH 1/1 usb/core: skip unnecessary line IRQ request for USB3

USB3 requests line IRQ here but will disable it in later driver->start function and try MSI first.

xhci_hcd 0000:02:00.0: irq 18, io mem 0xfe500000 xhci_hcd 0000:02:00.0: irq 45 for MSI/MSI-X xhci_hcd 0000:02:00.0: irq 46 for MSI/MSI-X

So it is better to remove the redundant request here. And save a little time in booting.

Signed-off-by Alex Shi <[email protected]>

---
 drivers/usb/core/hcd.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

drivers/usb/core/hcd.c +2 -1

index e128232..5b09825 100644
@@ -2450,7 +2450,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	/* enable irqs just before we start the controller,
 	 * if the BIOS provides legacy PCI irqs.
 	 */
-	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
+	if (usb_hcd_is_primary_hcd(hcd) && irqnum
+		&& (hcd->driver->flags & HCD_MASK) != HCD_USB3) {
 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
 		if (retval)
 			goto err_request_irq;

Signature · 1 line

1.7.5.1

Xu, Andiry

2012-03-15 06:22 UTC #1 lore raw

Quoted 9 lines

-----Original Message-----
From: [email protected] [mailto:linux-usb- [email protected]] On Behalf Of Alex Shi
Sent: Thursday, March 15, 2012 12:48 PM
To: [email protected]; gregkh
Cc: [email protected]; [email protected]; linux-usb
Subject: [PATCH] usb/core: skip unnecessary line IRQ request for USB3

Quoted 3 lines

USB3 requests line IRQ here but will disable it in later driver->start function and try MSI first.

You may also remove the unregister the legacy interrupt part in xhci_try_enable_msi().

In fact, I think all the MSI related codes should be moved to xhci-pci.c, Since MSI is PCI-only.

Thanks,
Andiry

Quoted 31 lines

xhci_hcd 0000:02:00.0: irq 18, io mem 0xfe500000
xhci_hcd 0000:02:00.0: irq 45 for MSI/MSI-X
xhci_hcd 0000:02:00.0: irq 46 for MSI/MSI-X
So it is better to remove the redundant request here. And save a little time in booting.
Signed-off-by Alex Shi <[email protected]>
---
 drivers/usb/core/hcd.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
drivers/usb/core/hcd.c +2 -2
index e128232..5b09825 100644
@@ -2450,7 +2450,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	/* enable irqs just before we start the controller,
 	 * if the BIOS provides legacy PCI irqs.
 	 */
-	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
+	if (usb_hcd_is_primary_hcd(hcd) && irqnum
+		&& (hcd->driver->flags & HCD_MASK) != HCD_USB3) {
 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
 		if (retval)
 			goto err_request_irq;
--
1.7.5.1

Quoted 4 lines

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Alex Shi

author

2012-03-15 06:37 UTC #2 lore raw

Quoted 4 lines

You may also remove the unregister the legacy interrupt part in xhci_try_enable_msi().

Sure, thanks!

Quoted 1 line

From 6ae16651ae33ea1841984f3a5eb4a691ed730a19 Mon Sep 17 00:00:00 2001

From: Alex Shi <[email protected]>
Date: Thu, 15 Mar 2012 08:12:47 +0800
Subject: [PATCH] usb/core: skip unnecessary line IRQ request for USB3

USB3(only xhci driver) requests line IRQ here but will disable it in later driver->start function and try MSI first:

xhci_hcd 0000:02:00.0: irq 18, io mem 0xfe500000 xhci_hcd 0000:02:00.0: irq 45 for MSI/MSI-X xhci_hcd 0000:02:00.0: irq 46 for MSI/MSI-X

So it is better to remove the redundant request here.

Signed-off-by Alex Shi <[email protected]>

---
 drivers/usb/core/hcd.c  |    3 ++-
 drivers/usb/host/xhci.c |    3 ---
 2 files changed, 2 insertions(+), 4 deletions(-)

drivers/usb/core/hcd.c +2 -1

index e128232..5b09825 100644
@@ -2450,7 +2450,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	/* enable irqs just before we start the controller,
 	 * if the BIOS provides legacy PCI irqs.
 	 */
-	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
+	if (usb_hcd_is_primary_hcd(hcd) && irqnum
+		&& (hcd->driver->flags & HCD_MASK) != HCD_USB3) {
 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
 		if (retval)
 			goto err_request_irq;

drivers/usb/host/xhci.c +0 -3

index c939f5f..64979c2 100644
@@ -338,9 +338,6 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 	if (xhci->quirks & XHCI_BROKEN_MSI)
 		return 0;
 
-	/* unregister the legacy interrupt */
-	if (hcd->irq)
-		free_irq(hcd->irq, hcd);
 	hcd->irq = -1;
 
 	ret = xhci_setup_msix(xhci);

Signature · 1 line

1.6.3.3

Quoted 3 lines

In fact, I think all the MSI related codes should be moved to xhci-pci.c, Since MSI is PCI-only.

A patch moving MSI from xhci to USB core is in reviewing. That walks far. :) https://lkml.org/lkml/2012/2/20/76

Alan Stern

2012-03-15 14:29 UTC #3 lore raw

In reply to Alex Shi

Quoted 20 lines · Alex Shi

USB3 requests line IRQ here but will disable it in later driver->start function and try MSI first.
xhci_hcd 0000:02:00.0: irq 18, io mem 0xfe500000 xhci_hcd 0000:02:00.0: irq 45 for MSI/MSI-X xhci_hcd 0000:02:00.0: irq 46 for MSI/MSI-X
So it is better to remove the redundant request here. And save a little time in booting.
Signed-off-by Alex Shi <[email protected]>
---
 drivers/usb/core/hcd.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
drivers/usb/core/hcd.c +0 -0
index e128232..5b09825 100644

drivers/usb/core/hcd.c int usb_add_hcd(struct usb_hcd *hcd, · line 2457

Quoted 9 lines

drivers/usb/core/hcd.c +2 -1

@@ -2450,7 +2450,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	/* enable irqs just before we start the controller,
 	 * if the BIOS provides legacy PCI irqs.
 	 */
-	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
+	if (usb_hcd_is_primary_hcd(hcd) && irqnum
+		&& (hcd->driver->flags & HCD_MASK) != HCD_USB3) {
 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
 		if (retval)
 			goto err_request_irq;

This is not a good idea. What happens if some USB-3 controller (perhaps a non-xHCI USB-3 controller) doesn't use MSI?

The right way to avoid registering a legacy interrupt handler is to call usb_add_hcd() with irqnum equal to 0.

Alan Stern

Alex Shi

author

2012-03-15 14:39 UTC #4 lore raw

Quoted 5 lines

This is not a good idea. What happens if some USB-3 controller (perhaps a non-xHCI USB-3 controller) doesn't use MSI?

current usb3 driver just xhci. but sure it need to modify if non-xhci usb pops up.

Quoted 2 lines

The right way to avoid registering a legacy interrupt handler is to call usb_add_hcd() with irqnum equal to 0.

a good trick! will try it tomorrow.

Quoted 3 lines

Alan Stern

Alex Shi

author

2012-03-16 08:06 UTC #5 lore raw

Quoted 6 lines · Alex Shi

Quoted 4 lines
This is not a good idea. What happens if some USB-3 controller (perhaps a non-xHCI USB-3 controller) doesn't use MSI?

Quoted 8 lines

current usb3 driver just xhci. but sure it need to modify if non-xhci usb pops up.
Quoted 2 lines
The right way to avoid registering a legacy interrupt handler is to call usb_add_hcd() with irqnum equal to 0.
a good trick! will try it tomorrow.

Do you mean the following patch? It tested. :)
------------

Quoted 1 line

From 5ae9a6fe88752495af6da6182cad26620f1ab190 Mon Sep 17 00:00:00 2001

From: Alex Shi <[email protected]>
Date: Thu, 15 Mar 2012 08:12:47 +0800
Subject: [PATCH] usb/core: skip unnecessary line IRQ request for USB3

USB3(only xhci driver) requests line IRQ here but will disable it in later driver->start function and try MSI first:

xhci_hcd 0000:02:00.0: irq 18, io mem 0xfe500000 xhci_hcd 0000:02:00.0: irq 45 for MSI/MSI-X xhci_hcd 0000:02:00.0: irq 46 for MSI/MSI-X

So it is better to remove the redundant request here.

Signed-off-by Alex Shi <[email protected]>

---
 drivers/usb/core/hcd-pci.c |    5 ++++-
 drivers/usb/host/xhci.c    |    3 ---
 2 files changed, 4 insertions(+), 4 deletions(-)

drivers/usb/core/hcd-pci.c +4 -1

index 81e2c0d..7b73c74 100644
@@ -245,7 +245,10 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 	pci_set_master(dev);
 
-	retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+	if ((driver->flags & HCD_MASK) != HCD_USB3)
+		retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+	else
+		retval = usb_add_hcd(hcd, 0, IRQF_SHARED);
 	if (retval != 0)
 		goto unmap_registers;
 	set_hs_companion(dev, hcd);

drivers/usb/host/xhci.c +0 -3

index c939f5f..64979c2 100644
@@ -338,9 +338,6 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 	if (xhci->quirks & XHCI_BROKEN_MSI)
 		return 0;
 
-	/* unregister the legacy interrupt */
-	if (hcd->irq)
-		free_irq(hcd->irq, hcd);
 	hcd->irq = -1;
 
 	ret = xhci_setup_msix(xhci);

Signature · 1 line

1.6.3.3

Quoted 8 lines

Quoted 4 lines
Alan Stern