tree 1e09865555d0c2dadf6d81445ad7f3f766058815
parent 7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9
author Mark Brown <broonie@linaro.org> 1408202861 +0100
committer Mark Brown <broonie@linaro.org> 1408482538 -0500

spi: Only call transfer_one() if we have buffers to transfer

Client drivers such as the ChomeOS EC driver sometimes use transfers with
no buffers and only a delay specified in order to allow a delay after the
assertion of /CS. Rather than require controller drivers handle this noop
case gracefully put checks in the core to ensure that we don't call into
the controller for such transfers.

Reported-by: Addy Ke <addy.ke@rock-chips.com>
Tested-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@linaro.org>