usb: xhci: Handle USB transaction error on address command

PATCH Superseded Lu Baolu 1 participant 2 messages Jul 25, 2017 – Jul 26, 2017 1 message not in the archive

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USB USB xHCI driver

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Lu Baolu

author

2017-07-25 05:12 UTC #0 lore raw

PATCH 1/1 usb: xhci: Handle USB transaction error on address command

Xhci driver handles USB transaction errors on transfer events, but transaction errors are possible on address device command completion events as well.

The xHCI specification (section 4.6.5) says: A USB Transaction Error Completion Code for an Address Device Command may be due to a Stall response from a device. Software should issue a Disable Slot Command for the Device Slot then an Enable Slot Command to recover from this error.

This patch handles USB transaction errors on address command completion events. The related discussion threads can be found through below links.

http://marc.info/?l=linux-usb&m=149362010728921&w=2
http://marc.info/?l=linux-usb&m=149252752825755&w=2

Signed-off-by Lu Baolu <[email protected]>

---
 drivers/usb/host/xhci.c | 6 ++++++
 1 file changed, 6 insertions(+)

drivers/usb/host/xhci.c +6 -0

index b2ff1ff..9cc56cd 100644
@@ -3836,6 +3836,12 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
 		ret = -EINVAL;
 		break;
 	case COMP_USB_TRANSACTION_ERROR:
+		xhci_free_virt_device(xhci, udev->slot_id);
+		ret = xhci_disable_slot(xhci, command, udev->slot_id);
+		udev->slot_id = 0;
+		if (!ret)
+			xhci_alloc_dev(hcd, udev);
+
 		dev_warn(&udev->dev, "Device not responding to setup %s.\n", act);
 		ret = -EPROTO;
 		break;

Signature · 1 line

2.7.4

A message that is not in the archive (sent off-list or not yet received): [email protected]

Lu Baolu

author

2017-07-26 05:19 UTC #2 lore raw

Hi,

Quoted 38 lines · Zhengjun

Quoted 28 lines · Lu Baolu
Xhci driver handles USB transaction errors on transfer events, but transaction errors are possible on address device command completion events as well.
The xHCI specification (section 4.6.5) says: A USB Transaction Error Completion Code for an Address Device Command may be due to a Stall response from a device. Software should issue a Disable Slot Command for the Device Slot then an Enable Slot Command to recover from this error.
This patch handles USB transaction errors on address command completion events. The related discussion threads can be found through below links.
http://marc.info/?l=linux-usb&m=149362010728921&w=2
http://marc.info/?l=linux-usb&m=149252752825755&w=2
Suggested-by Mathias Nyman <[email protected]>
Signed-off-by Lu Baolu <[email protected]>
---
  drivers/usb/host/xhci.c | 6 ++++++
  1 file changed, 6 insertions(+)
drivers/usb/host/xhci.c +0 -0
index b2ff1ff..9cc56cd 100644
drivers/usb/host/xhci.c static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev, · line 3839
Quoted 4 lines
drivers/usb/host/xhci.c +1 -0
@@ -3836,6 +3836,12 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
          ret = -EINVAL;
          break;
      case COMP_USB_TRANSACTION_ERROR:
+        xhci_free_virt_device(xhci, udev->slot_id);
In xhci_free_virt_device xhci->devs[slot_id]will be set to NULL.

Quoted 3 lines

drivers/usb/host/xhci.c static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev, · line 3840
Quoted 1 line
drivers/usb/host/xhci.c +1 -0
+        ret = xhci_disable_slot(xhci, command, udev->slot_id);
When xhci_disable_slot check xhci->devs[slot_id] is NULL, just return -EINVAL, the slot will not be disabled.

Yes, really.

I don't think xhci_disable_slot() should return directly when the virtual device structure is not allocated. This function is also used to issue a disable slot command when the virtual device data allocation fails in xhci_alloc_dev().

I will develop v2 patch with a fix for xhci_disable_slot().

Best regards,
Lu Baolu