Revert "i2c: i2c-qcom-geni: Fix DMA transfer race"
authorDouglas Anderson <dianders@chromium.org>
Tue, 13 Oct 2020 21:25:29 +0000 (14:25 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 30 Dec 2020 10:52:57 +0000 (11:52 +0100)
commit942e8f31dff6a378e66d93982f0e69a459f8a5f2
tree95c48befd7b994c494c775e82ce971a7b2d25951
parent614199a8d1d19a1b007f157866fd66e703b2d0af
Revert "i2c: i2c-qcom-geni: Fix DMA transfer race"

[ Upstream commit 9cb4c67d7717135d6f4600a49ab07b470ea4ee2f ]

This reverts commit 02b9aec59243c6240fc42884acc958602146ddf6.

As talked about in the patch ("soc: qcom: geni: More properly switch
to DMA mode"), swapping the order of geni_se_setup_m_cmd() and
geni_se_xx_dma_prep() can sometimes cause corrupted transfers.  Thus
we traded one problem for another.  Now that we've debugged the
problem further and fixed the geni helper functions to more disable
FIFO interrupts when we move to DMA mode we can revert it and end up
with (hopefully) zero problems!

To be explicit, the patch ("soc: qcom: geni: More properly switch
to DMA mode") is a prerequisite for this one.

Fixes: 02b9aec59243 ("i2c: i2c-qcom-geni: Fix DMA transfer race")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20201013142448.v2.2.I7b22281453b8a18ab16ef2bfd4c641fb1cc6a92c@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/i2c/busses/i2c-qcom-geni.c