Re: [RFC} sdhci.c set_ios -- disable global interrupts and Question on Power Management

[Philip Rakity <prakity@marvell.com>]

Pierre,

The spin_lock may not be needed if the same thread cannot be re-entered.

That was the reason for the assumptions.  Sorry about not being clear.

Philip

On Feb 14, 2011, at 10:41 AM, Tardy, Pierre wrote:

> Philip,
>>> And, more important, you will do cond_resched while holding you
>>> spinlock, which is *bad*.
>>> What if the mmc stack will call you again from another thread? deadlock...
> 
>> Assumptions -- Please Confirm
>> -------------------------------------------
> No need to do assumptions, schedule while holding spinlocks is bad, your kernel will oops with something like:
> BUG: scheduling while in atomic.
> 
> 
>>>> @@ -1108,7 +1108,7 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned short power)
>>>>        * can apply clock after applying power
>>>>        */
>>>>       if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
>>>> -               mdelay(10);
>>>> +               mmc_delay(10);
>>> Do you need this quirk in your platform?
>> 
>> No
> Then, you dont have any mdelay in your set_ios, and you are trying to optimize something that never happen.
> 
> Pierre
> 
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