In multi-master environment, this driver's master cannot know exactly when peer master sends data to this driver's slave so a case can be happened that this master tries to send data through the master_xfer function but slave data from peer master is still being processed by this driver. To prevent state corruption in the case, this patch adds checking code if any slave operation is ongoing and it waits up to the timeout duration before starting a master_xfer operation. Please review this patch set. Thanks, -Jae Changes since v3: - Changed the property name to 'timeout' and made it use the default setting in i2c-core when not specified. Changes since v2: - Changed the property name to 'aspeed,timeout' and made it to update the adapter's timeout configuration. Changes since v1: - Changed define names of timeout related. Jae Hyun Yoo (3): dt-bindings: i2c: aspeed: Add 'timeout' property as an optional property i2c: aspeed: Add 'timeout' DT property reading code i2c: aspeed: Add bus idle waiting logic for multi-master use cases .../devicetree/bindings/i2c/i2c-aspeed.txt | 3 + drivers/i2c/busses/i2c-aspeed.c | 70 ++++++++++++++----- 2 files changed, 57 insertions(+), 16 deletions(-) -- 2.19.0