Re: [PATCH 3/7] ark3116: (3rd try) Replace cmget

[Bart Hartgers]

2009/10/25 Oliver Neukum <oliver@xxxxxxxxxx>:
> Am Sonntag, 25. Oktober 2009 18:51:00 schrieb bart.hartgers@xxxxxxxxx:
>> +ÂÂÂÂÂÂÂ/* read modem status */
>> +ÂÂÂÂÂÂÂunsigned status = atomic_read(&priv->msr);
>> +ÂÂÂÂÂÂÂ/* modem control is output */
>> +ÂÂÂÂÂÂÂunsigned ctrl = atomic_read(&priv->mcr);
>
> What is the sense of having two atomic variables?
> You can get races where one is changed but the other is not.
>
> Â Â Â ÂRegards
> Â Â Â Â Â Â Â ÂOliver
>
>

Hi Oliver,

I don't think so. The two values are not really related.

These are two separate things: mcr (modem control reg) is ultimately
changed by whatever has the serial port open, msr (modem status
register) represents the status of the handshaking lines, and is
changed (via the interrupt urb callback) by hardware.

Groeten,
Bart

-- 
Bart Hartgers - New e-mail: bart.hartgers@xxxxxxxxx
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