On 2021-05-28 13:41, Wolfram Sang wrote:

On Tue, May 25, 2021 at 06:40:50PM +0530, Roja Rani Yarubandi wrote:

quoted

If the hardware is still accessing memory after SMMU translation
is disabled (as part of smmu shutdown callback), then the
IOVAs (I/O virtual address) which it was using will go on the bus
as the physical addresses which will result in unknown crashes
like NoC/interconnect errors.

So, implement shutdown callback for i2c driver to suspend the bus
during system "reboot" or "shutdown".

Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the 
Qualcomm GENI I2C controller")
Signed-off-by: Roja Rani Yarubandi <redacted>

Do we need patch 1 after patch 2 was applied? I always thought all
devices are suspended before shutdown/reboot?

Yes, both patch 1 and patch 2 are required.
Devices are not suspended during shutdown/reboot.

Nice to see that 'mark_adapter_suspended' becomes useful again!

Thanks,
Roja