Hi,

On Thu, Aug 23, 2018 at 03:57:31PM -0700, Jae Hyun Yoo wrote:

In most of cases, interrupt bits are set one by one but there are
also a lot of other cases that Aspeed I2C IP sends multiple
interrupt bits with combining master and slave events using a
single interrupt call. It happens much more in multi-master
environment than single-master. For an example, when master is
waiting for a NORMAL_STOP interrupt in its MASTER_STOP state,
SLAVE_MATCH and RX_DONE interrupts could come along with the
NORMAL_STOP in case of an another master immediately sends data
just after acquiring the bus. In this case, the NORMAL_STOP
interrupt should be handled by master_irq and the SLAVE_MATCH and
RX_DONE interrupts should be handled by slave_irq. This commit
modifies irq hadling logic to handle the master/slave combined
events properly.

Signed-off-by: Jae Hyun Yoo <redacted>
Reviewed-by: Brendan Higgins <redacted>

This patch causes a boot stall when booting witherspoon-bmc with
qemu v3.0, and all i2c device probes fail with error -110 (timeout).
Bisect log is attached for reference.

With the same kernel configuration (aspeed_g5_defconfig),
ast2500-evb and romulus-bmc are still able to boot.
palmetto-bmc with aspeed_g4_defconfig also appears to work.

Is this a problem with qemu ? Should I drop the qemu test
for witherspoon-bmc starting with the next kernel release ?

Thanks,
Guenter

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# bad: [09c0888767529cdb382f34452819e42d1a66a114] Add linux-next specific files for 20180911
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# first bad commit: [3e9efc3299dd78a0fa96515f0a453fab1ed4a1bd] i2c: aspeed: Handle master/slave combined irq events properly