Hi Sarah,
First of all thank you very much for the prompt response!
Please see comments bellow.
> > I'm trying to switch to the second configuration using sysfs (by
> writing to
> > bConfigurationValue in /sys/bus/usb/devices/10-1/).
>
> Oh, interesting, I wasn't aware users could do that.
I found it out myself just recently :) I was looking for whoever calls
usb_set_configuration() and found out that it's called from sysfs.c -
set_bConfigurationValue().
This works with dummy_hcd() but there it's all much simpler.
> > [ 65.694680] xhci_hcd 0000:01:00.0: Wrote link toggle flag to
> segment ffff880122acc460 (virtual), 0xc5021000 (DMA)
> > [ 65.694683] xhci_hcd 0000:01:00.0: WARN no SS endpoint bMaxBurst
>
> Do you have a SuperSpeed Endpoint Companion descriptor for all your
> endpoints? Because this message seems to indicate you don't. Can you
> send me the lsusb -vvv for your device?
Lsusb log is attached. We do have SS Endpoint Companion descriptor, I think
the warning here is because the bMaxBurst field of the Endpoint Companion
descriptor is 0.
> > [ 108.742142] xhci_hcd 0000:01:00.0: Wrote link toggle flag to
> segment ffff880037bde560 (virtual), 0x37a93400 (DMA)
> > [ 108.742146] xhci_hcd 0000:01:00.0: WARN no SS endpoint bMaxBurst
>
> More issues with the SuperSpeed Endpoint Companion descriptors here.
Is it a problem that we report that bMaxBurst is 0?
>
> > [ 108.742216] xhci_hcd 0000:01:00.0: add ep 0x2, slot id 1, new drop
> flags = 0x0, new add flags = 0x3c, new slot info = 0x28400000
>
> I'm a bit surprised that the endpoints from the previous configuration
> weren't dropped before this new configuration was added. But drivers
> usually go through usb_set_configuration(), and maybe the sysfs
> interface hits a different path? I'll have to look into the code flow.
Nope, the same. Here is the code from sysfs.c that handles this:
static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int config, value;
if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
return -EINVAL;
usb_lock_device(udev);
value = usb_set_configuration(udev, config);
usb_unlock_device(udev);
return (value < 0) ? value : count;
}
> Ok, I'll take a look into fixing this tomorrow. I'll probably send you
> two patches: one to add an additional check in xhci_add_endpoint(), and
> another once I figure out the root cause of why the first configuration
> isn't getting removed. Can you test with just the first patch, to make
> sure the check works?
No problem. Thank you very much! Waiting for the patches...
Thanks,
Tanya Brokhman
---
Sent by an consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
Bus 010 Device 003: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB File Storage Gadget
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x0525 Netchip Technology, Inc.
idProduct 0xa4a5 Linux-USB File Storage Gadget
bcdDevice 0.00
iManufacturer 2 Linux 2.6.39+ with pcd
iProduct 3 Mass Storage Gadget
iSerial 0
bNumConfigurations 2
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 44
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 1 Mass Storage
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 00 00 00
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 00 00 00
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 86
bNumInterfaces 1
bConfigurationValue 2
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 4
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 98
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 10 00 00
INTERFACE CLASS: 04 24 03 00
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 10 00 00
INTERFACE CLASS: 04 24 04 00
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 10 00 00
INTERFACE CLASS: 04 24 02 00
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
** UNRECOGNIZED: 06 30 00 10 00 00
INTERFACE CLASS: 04 24 01 00
Device Status: 0x0001
Self Powered
