usbnet: mcs7830: rework link state detection
usbnet: mcs7830: rework link state detection

Even with the quirks in commit dabdaf0c (mcs7830: Fix link state
detection) there are still spurious link-down events for some chips
where the false link-down events count go over a few hundreds.

This patch takes a more conservative approach and only looks at
link-down events where the link-down state is not combined with other
states (e.g. half/full speed, pending frames in SRAM or TX status
information valid). In all other cases we assume the link is up.

Tested on MCS7830CV-DA (USB ID 9710:7830).

Cc: Ondrej Zary <ba324ca7b1c77fc20bb970d5aff6eea9377918a5@rainbow-software.org>
Cc: Michael Leun <6dacfe0c21fb9b546263fe25390cb258e045c7dc@newton.leun.net>
Cc: Ming Lei <8d0fc11caeb4659419f0ba3104eb4a9d30848d42@canonical.com>
Signed-off-by: Octavian Purdila <77c06d0261d8d3a9171f87dd4ca9bbbd1924db77@intel.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs