Re: [PATCH 4/6] myri10ge - First half of the driver

From: Brice Goglin
Date: Mon May 15 2006 - 13:39:46 EST


Lee Revell wrote:
> On Fri, 2006-05-12 at 01:53 +0200, Brice Goglin wrote:
>
>> Francois Romieu wrote:
>>
>>>> + spin_lock(&mgp->cmd_lock);
>>>> + response->result = 0xffffffff;
>>>> + mb();
>>>> + myri10ge_pio_copy((void __iomem *) cmd_addr, buf, sizeof (*buf));
>>>> +
>>>> + /* wait up to 2 seconds */
>>>>
>>>>
>>> You must not hold a spinlock for up to 2 seconds.
>>>
>>>
>> We are working on reducing the delay to about 15ms. It only occurs when
>> the driver is loaded or the link brought up.
>>
>
> I think 15ms is quite a long time to hold a spinlock also - most
> spinlocks in the kernel are held for less than 500 microseconds.
>
> Can't you use a mutex?
>

It looks like rtnl_lock protects us here. We are working on it.

Brice

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