Regression due to 59cf44575456 ("USB: core: Fix oversight in SuperSpeed initialization")

[Oliver Neukum <oneukum@suse.com>]

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Hi,

with the following device:

Bus 002 Device 002: ID fb5d:0001 BHYVE HID Tablet
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               3.00
   bDeviceClass            0
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0         8
   idVendor           0xfb5d
   idProduct          0x0001
   bcdDevice            0.00
   iManufacturer           1 BHYVE
   iProduct                2 HID Tablet
   iSerial                 3 01
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength       0x0028
     bNumInterfaces          1
     bConfigurationValue     1
     iConfiguration          4 HID Tablet Device
     bmAttributes         0xa0
       (Bus Powered)
       Remote Wakeup
     MaxPower                0mA
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           1
       bInterfaceClass         3 Human Interface Device
       bInterfaceSubClass      1 Boot Interface Subclass
       bInterfaceProtocol      2 Mouse
       iInterface              0
         HID Device Descriptor:
           bLength                 9
           bDescriptorType        33
           bcdHID              10.01
           bCountryCode            0 Not supported
           bNumDescriptors         1
           bDescriptorType        34 Report
           wDescriptorLength      74
          Report Descriptors:
            ** UNAVAILABLE **
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0008  1x 8 bytes
         bInterval              10
         bMaxBurst               0
Binary Object Store Descriptor:
   bLength                 5
   bDescriptorType        15
   wTotalLength       0x000f
   bNumDeviceCaps          1
   SuperSpeed USB Device Capability:
     bLength                10
     bDescriptorType        16
     bDevCapabilityType      3
     bmAttributes         0x00
     wSpeedsSupported   0x0008
       Device can operate at SuperSpeed (5Gbps)
     bFunctionalitySupport   3
       Lowest fully-functional device speed is SuperSpeed (5Gbps)
     bU1DevExitLat          10 micro seconds
     bU2DevExitLat          32 micro seconds
Device Status:     0x0000
   (Bus Powered)

we are getting a regression on enumeration. It used to work with the
code prior to your patch. Takashi is proposing the attached fixed.
It looks like we are a bit too restrictive and should just try.

	Regards
		Oliver

[-- Attachment #2: 0001-USB-hub-Workaround-for-buggy-max-packet-size-with-su.patch --]
[-- Type: text/x-patch, Size: 1982 bytes --]

From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] USB: hub: Workaround for buggy max packet size with super
 speed
Patch-mainline: Not yet, testing
References: bsc#1220569

Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/core/hub.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index e38a4124f610..64193effc456 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4830,7 +4830,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 	const char		*driver_name;
 	bool			do_new_scheme;
 	const bool		initial = !dev_descr;
-	int			maxp0;
+	int			maxp0, ep0_maxp;
 	struct usb_device_descriptor	*buf, *descr;
 
 	buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
@@ -5070,7 +5070,8 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 		else
 			i = 0;		/* Invalid */
 	}
-	if (usb_endpoint_maxp(&udev->ep0.desc) == i) {
+	ep0_maxp = usb_endpoint_maxp(&udev->ep0.desc);
+	if (ep0_maxp == i) {
 		;	/* Initial ep0 maxpacket guess is right */
 	} else if ((udev->speed == USB_SPEED_FULL ||
 				udev->speed == USB_SPEED_HIGH) &&
@@ -5082,9 +5083,15 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
 		usb_ep0_reinit(udev);
+	} else if (udev->speed >= USB_SPEED_SUPER && initial) {
+		/* FIXME: should be more restrictive? */
+		/* Initial guess is wrong; use the descriptor's value */
+		dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
+		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
+		usb_ep0_reinit(udev);
 	} else {
 		/* Initial guess is wrong and descriptor's value is invalid */
-		dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", maxp0);
+		dev_err(&udev->dev, "Invalid ep0 maxpacket: %d, expected %d\n", maxp0, ep0_maxp);
 		retval = -EMSGSIZE;
 		goto fail;
 	}
-- 
2.35.3