Re: [patch 4/5] net: hip04: Make tx coalesce timer actually work

From: Ding Tianhong
Date: Tue Apr 14 2015 - 03:54:30 EST


On 2015/4/14 6:08, Thomas Gleixner wrote:
> On Tue, 14 Apr 2015, Arnd Bergmann wrote:
>> On Monday 13 April 2015 23:42:03 Thomas Gleixner wrote:
>>>>
>>>> Question: this looks to me like it sets both the minimum and maximum
>>>> time to priv->tx_coalesce_usecs/2, when the intention was to set
>>>> the minimum to priv->tx_coalesce_usecs/2 and the maximum to
>>>> priv->tx_coalesce_usecs. Am I missing something subtle here, or did
>>>> you just misread my original intention from the botched code?
>>>
>>> Yes, I missed that. Simple fix for this is:
>>>
>>> unsigned long t_ns = priv->tx_coalesce_usecs * NSEC_PER_USEC / 2;
>>>
>>> hrtimer_start_range_ns(&priv->tx_coalesce_timer, ns_to_ktime(t_ns),
>>> t_ns, HRTIMER_MODE_REL);
>>
>> Ah, good. I have to admit that I'd probably make the same mistake
>> again if I was to do this for another driver and you hadn't sent
>> the fix. The hrtimer_set_expires_range() function just looked like
>> it had been designed for the use case I was interested in ;-).
>>
>> Any idea how to prevent the next person from making the same mistake?
>
> Yes. Documentation :)
>
Looks good to me, thanks everyone.

Ding

> Thanks,
>
> tglx
>
> .
>


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