Oliver Neukum <oliver@xxxxxxxxxx> writes:
> Am Sonntag, 15. Januar 2012, 07:40:36 schrieb Bjørn Mork:
>> USB CDC Ethernet devices may encapsulate vendor specific protocols inside
>> USB_CDC_SEND_ENCAPSULATED_COMMAND +USB_CDC_GET_ENCAPSULATED_RESPONSE
>> control messages. Devices based on Qualcomm MSM
>> chipsets are known to use this for exporting the Qualcomm
>> MSM Interface (QMI) protocol. Examples of such devices are
>> the Huawei E392 and E398 LTE modems.
>
> The problem is that this is another version of the code already
> in cdc-wdm, which is tested well.
Huh? I thought that was something entirely different. Isn't it?
Anyway, I see that I should look thoroughly at it as it does these
things in a much nicer way. Thanks for the pointer.
> I'd really like to unify this stuff.
That makes sense.
[snipped a number of detailed issues which I obviously need to fix]
>> +
>> +/* per CDC_ENC interface state */
>> +struct cdc_enc_state {
>> + struct usb_interface *intf;
>> + struct urb *urb; /* receive urb */
>> + struct urb *interrupt; /* interrupt urb */
>> + unsigned char rcvbuf[CDC_ENC_BUFLEN]; /* receive buffer */
>
> This is a violation of the DMA requirements. You must use kmalloc.
This probably only demonstrates my lack of understanding these
requirements. I thought this was OK as long as I kmalloc'ed the whole
struct, but I see now that that isn't necessarily true.
>
> I had a not very detailed look at this driver, but I would really prefer
> if you could have a look at making unified code for this, cdc-wdm and cdc-acm.
Will do. Thanks a lot for the fast review.
Bjørn
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