On 09/13/2018 09:35 AM, Cédric Le Goater wrote: > On 09/13/2018 05:57 PM, Guenter Roeck wrote: >> On Thu, Sep 13, 2018 at 05:48:59PM +0200, Cédric Le Goater wrote: >>> On 09/13/2018 03:33 PM, Guenter Roeck wrote: >> [ ... ] >>>>>>   /* >>>>>>    * The state machine needs some refinement. It is only used to track >>>>>>    * invalid STOP commands for the moment. >>>>>> @@ -188,7 +215,7 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) >>>>>>   { >>>>>>       bus->cmd &= ~0xFFFF; >>>>>>       bus->cmd |= value & 0xFFFF; >>>>>> -    bus->intr_status = 0;> +    bus->intr_status &= I2CD_INTR_RX_DONE; >>>>> >>>>> it deserves a comment to understand which scenario we are trying to handle. >>>>> >>>> >>>> Ok. FWIW, I wonder if intr_status should be touched here in the first place, >>>> but I neither have the hardware nor a datasheet, so I don't know if any bits >>>> are auto-cleared. >>> >>> I just pushed a patch on my branch with some more explanation : >>> >>> https://github.com/legoater/qemu/commits/aspeed-3.1 >>> >> That seems to suggest that none of the status bits auto-clears, and that >> the above code clearing intr_status should be removed entirely. >> Am I missing something ? > > You are right. I just pushed another version of the previous patch with this > new hunk : > > @@ -188,7 +200,6 @@ static void aspeed_i2c_bus_handle_cmd(As > { > bus->cmd &= ~0xFFFF; > bus->cmd |= value & 0xFFFF; > - bus->intr_status = 0; > > if (bus->cmd & I2CD_M_START_CMD) { > uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ? > > > The QEMU palmetto and witherspoon machines seem to behave fine. Can you give > it a try ? > Works fine for me for all affected qemu platforms. How do you want to proceed with the qemu patches ? I attached my patches for reference. Maybe you can add them to your tree if they are ok and submit the entire series together to the qemu mailing list ? Thanks, Guenter