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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH 1/3] MSI driver for Freescale 83xx/85xx/86xx cpu
Date: Tue, 22 Apr 2008 15:22:16 +0200
To: michael@ellerman.id.au
Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>,
	Kumar Gala <kumar.gala@freescale.com>,
	Jin Zhengxiong <Jason.Jin@freescale.com>
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>>>> +static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
>>>> +				  struct msi_msg *msg)

> No I mean I'm confused about the maths here. If we pull out the
> variables it boils down to:
>
> data = ((hwirq / 32) << 5) | ((hwirq % 32) & 0x1F)
>
> Which doesn't seem to actually do anything?

It's not a no-op, because hwirq is signed.  It probably should be
unsigned, like most things.


Segher