Re: [PATCH i2c-next v6] i2c: aspeed: Handle master/slave combined irq events properly

From: Guenter Roeck
Date: Thu Sep 13 2018 - 11:57:13 EST


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 ?

Thanks,
Guenter