Replace (cond ? 1 : 0) with cond or !!cond as appropriate, and
(cond ? 0 : 1) with !cond.

Remove some redundant boolean temporaries.

Rename one field that looks like a flag but isn't.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add efx_poll_loopback() function to test for successful completion of test.
Change efx_test_loopback() to end the test after 1 ms if
efx_poll_loopback() indicates success, and otherwise to wait for 100 ms
as before.

While we're here, rename efx_{rx,tx}_loopback() to
efx_{begin,end}_loopback() which more accurately reflect their
purpose.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Removed log messages that are redundant with calling functions.
Fixed bitwise or-ing of return codes.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

efx_test_loopback() used "|" to combine the results of the RX and TX
phases.  If both phases fail with different error codes, this results
in a bogus error code.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Checksum generation is an attribute of our hardware TX queues, not TX
descriptors.  We previously used a single queue and turned checksum
generation on or off as requested through ethtool.  However, this can
result in regenerating checksums in raw packets that should not be
modified.  We now create 2 hardware TX queues with checksum generation
on or off.  They are presented to the net core as one queue since it
does not know how to select between them.

The self-test verifies that a bad checksum is unaltered on the queue
with checksum generation off.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add a set of self-tests accessible thorugh ethtool.
Add hardware loopback and TX disable control code to support them.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>