[PATCH v2 0/2] NVIDIA Tegra I2C synchronization correction

Dmitry Osipenko
2020-03-24T19:13:30Z

Hello,

Recently I found a way to reliably reproduce I2C timeouts that happen due
to improper synchronizations made by the I2C driver. It's quite easy to
reproduce the problem when memory is running on a lower freq + there is
some memory activity + CPU could get busy for a significant time. This
is the case when KASAN is enabled and CPU is busy while accessing FS via
NFS. This small series addresses the found problems.

Changelog:

v2: - The "Better handle case where CPU0 is busy for a long time" patch
now preserves the old behavior where completion is checked after
disabling the interrupt, preventing potential race-condition of
the completion awaiting vs interrupt syncing.

Dmitry Osipenko (2):
i2c: tegra: Better handle case where CPU0 is busy for a long time
i2c: tegra: Synchronize DMA before termination

drivers/i2c/busses/i2c-tegra.c | 36 ++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)

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2.25.1