Merge branch 'net-ipa-gsi-channel-flow-control'

Merge branch 'net-ipa-gsi-channel-flow-control'

Alex Elder says:

====================
net: ipa: GSI channel flow control

Starting with IPA v4.2, endpoint DELAY mode (which prevents data
transfer on TX endpoints) does not work properly.  To address this,
changes were made to allow underlying GSI channels to be put into
a "flow controlled" state, which achieves a similar objective.
The first patch in this series implements the flow controlled
channel state and the commands used to control it.  It arranges
to use the new mechanism--instead of DELAY mode--for IPA v4.2+.

In IPA v4.11, the notion of GSI channel flow control was enhanced,
and implemented in a slightly different way.  For the most part this
doesn't affect the way the IPA driver uses flow control, but the
second patch adds support for the newer mechanism.
====================

Link: https://lore.kernel.org/r/20211124194416.707007-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>