Re: [PATCH v1 i2c/for-next] i2c-i801: recover from hardware PEC errors

[Daniel Kurtz <djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>]

Hi guys,

On Fri, Apr 24, 2015 at 6:08 PM, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org> wrote:
> Hi Ellen,
>
> On Mon, 20 Apr 2015 15:52:47 -0700, Ellen Wang wrote:
>> This leads to a related question:  If the driver is serialized, then the
>> (status = priv->status) inside wait_event_timeout() isn't strictly
>> necessary, correct?  It can just be priv->status.  I'm just want to
>> double check that there's no race and I can add a priv->auxsts and not
>> have to stick something like this inside the wait_event_timeout():
>>
>>     (auxsts = priv->auxsts, status = priv->status)
>
> To be honest I'm not 100% certain. I think this was only a minor
> optimization, but I may be wrong. Adding Daniel to Cc, he added that
> code to the i2c-i801 driver. Daniel, any comment on this?
>
> Equally mysterious to me is:
>
>                 priv->status |= status;
>
> in i801_isr() where it would seem that a simple "=" would suffice.

Sorry, it has been a long time since i looked at i801 code,
I think you guys are correct.  You can probably just do:

            wait_event(priv->waitq, priv->status);
            status = priv->status;
            priv->status = 0;
            return i801_check_post(priv, status);

And, I agree with Jean in i801_isr(),
   priv->status |= status;

Could probably just be:
   priv->status = status;

-Dan

>
> --
> Jean Delvare
> SUSE L3 Support