Re: usb_wwan regression in 3.6 kernel (bisected to bulk-urb allocation)

["Bjørn Mork" <bjorn-yOkvZcmFvRU@public.gmane.org>]

Rafał Miłecki <zajec5-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        0
>       bAlternateSetting       0
>       bNumEndpoints           0
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass    255 Vendor Specific Subclass
>       bInterfaceProtocol    255 Vendor Specific Protocol
>       iInterface              0 
>       ** UNRECOGNIZED:  05 24 00 10 01
>       ** UNRECOGNIZED:  05 24 15 00 01
>       ** UNRECOGNIZED:  05 24 06 00 00
>       ** UNRECOGNIZED:  15 24 12 20 01 98 b0 6a 49 b0 9e 48 96 94 46 d9 9a 28 ca 4e 5d
>       ** UNRECOGNIZED:  06 24 13 00 01 10
>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        0
>       bAlternateSetting       1
>       bNumEndpoints           2
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass    255 Vendor Specific Subclass
>       bInterfaceProtocol    255 Vendor Specific Protocol
>       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     0x0200  1x 512 bytes
>         bInterval              32
>       Endpoint Descriptor:
>         bLength                 7
>         bDescriptorType         5
>         bEndpointAddress     0x01  EP 1 OUT
>         bmAttributes            2
>           Transfer Type            Bulk
>           Synch Type               None
>           Usage Type               Data
>         wMaxPacketSize     0x0200  1x 512 bytes
>         bInterval              32
>   


Hmm, AFAICS we never change altsettings in the option/usb_wwan/
usb-serial probing, so this function ends up without any endpoints at all.
As such it should just have failed the probe.  But the option driver has
a static num_ports = 1, which looks like it is overriding the endpoint
based calculation in usb_serial_probe() even for the case where
num_bulk_out == 0.  That cannot be right...

I believe we should both change altsettings and fail if there still
aren't enough endpoints available.


Bjørn
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