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Date: Fri, 19 Oct 2007 17:53:08 -0700 (PDT)
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Subject: Re: [BUG] powerpc does not save msi state [was Re: [PATCH 5/7]
	pci: Export the pci_restore_msi_state() function
From: David Miller <davem@davemloft.net>
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From: linas@austin.ibm.com (Linas Vepstas)
Date: Fri, 19 Oct 2007 19:46:10 -0500

> FWIW, it looks like not all that many arches do this; the output
> for grep -r address_hi * is pretty thin. Then, looking at
> i386/kernel/io_apic.c as an example, one can see that the 
> msi state save happens "by accident" if CONFIG_SMP is enabled;
> and so its surely broekn on uniprocesor machines.

I don't see this, in all cases write_msi_msg() will transfer
the given "*msg" to entry->msg by this assignment in
drivers/pci/msi.c:

void write_msi_msg(unsigned int irq, struct msi_msg *msg)
{
 ...
	entry->msg = *msg;
}

So as long as write_msi_msg() is invoked, it will be saved
properly.

Platforms need not do this explicitly.