Re: [PATCH] x86: serialize EFI time accesses on rtc_lock

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Tue, Jul 19, 2011 at 11:32:05PM +0600, Rakib Mullick wrote:

> If I'm not missing anything, this implementation (serialization) could
> be simpler by holding rtc_lock at the time of calling those functions.
> I mean, holding rtc_lock before calling EFI services
> virt_efi_get/set_time and virt_efi_get/set_wakeup_time - something
> like below:
> 
>              spin_lock_irqsave(&rtc_lock, flags);
>              efi.get_time = virt_efi_get_time;
>              efi.set_time = virt_efi_set_time;
>              efi.get_wakeup_time = virt_efi_get_wakeup_time;
>              efi.set_wakeup_time = virt_efi_set_wakeup_time;
>             spin_unlock_irqrestore(&rtc_lock, flags);

That's just assigning some function pointers, not actually making the 
calls. There's potentially several routes to each of the calls, so it 
makes sense to do the locking there.

-- 
Matthew Garrett | mjg59@srcf.ucam.org