Re: forcedeth: option to disable 100Hz timer (try 2)

Robert Hancock
2008-09-11T00:18:35Z

Andrew Morton wrote:
> On Tue, 9 Sep 2008 23:34:35 +0400
> Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com> wrote:
>
>> On some hardware no TX done interrupts are generated, thus special
>> 100Hz timer interrupt is required to handle this situation properly.
>> Other device do not require that timer interrupt feature.
>>
>> Forcedeth has a DEV_NEED_TIMERIRQ flag to mark the broken devices.
>> Unfortunately, nobody know the actual list of broken devices, so all
>> device has this flag on. Other problem, this flag is not user visible,
>> so the kernel recompilation is required to disable timer interrupts and
>> test a device.
>>
>> This patch add a "disable_timerirq" option to disable interrupt
>> timer mentioned above. This may be extremely useful for laptop users.
>
> Why do you feel that the timer-based completions need to be disabled?
> Is it causing some problem?

100 unnecessary CPU wakeups per second imposes some power usage cost,
especially on laptops with CPU C-states..