Re: [PATCH net-next 02/14] net: cdc_ncm: use device rx_max value if update failed

Alexey Orishko [off-list ref] writes:

On Fri, Oct 19, 2012 at 2:18 PM, Bjørn Mork [off-list ref] wrote:

quoted

OK, I may have misunderstood you here.  Quoting the errata text:

<quote>
  If bit D5 is set in the bmNetworkCapabilities field of function’s NCM
  Functional Descriptor, the host may set wLength either to 4 or to
  8. If wLength is 4, the function shall assume that wNtbInMaxDatagrams
  is to be set to zero. If wLength is 8, then the function shall use the
  provided value as the limit. The function shall return an error
  response (a STALL PID) if wLength is set to any other value.
</quote>

So the 4 byte variant is always supported and we might as well just use
it unconditionally because we don't set, or need to set, the
wNtbInMaxDatagrams.

Is that right?  It will simplify the code even more without any loss of
functionality, except for the possibility of failing on some other buggy
device not supporting the 4 byte variant...

Agree, since 4-byte version must be supported by all devices,
we can drop 8-byte variant

Thanks.  I'll implement that in the next version then, and drop the
first patch as it is no longer needed.

But I will hold off posting the updated series for a few more days to
allow you all some time to digest the rest of this. There should be more
issues to comment on here than this simple firmware bug workaround ;-)


Bjørn
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