On 09/11/2018 08:37 PM, Guenter Roeck wrote:

Hi,

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

quoted

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 ?

The QEMU model for the Aspeed I2C controller does not support 
slave mode or DMA registers. That might be the issue. 

I will check what this patch does when I have sometime. 

Thanks, 


C.