Messages in this thread | | | Date | Sat, 27 Sep 2008 08:35:00 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH] pci: introduce an ioremap_pcibar(pdev, barnr) function |
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On Fri, 26 Sep 2008 20:56:14 -0600 Matthew Wilcox <matthew@wil.cx> wrote:
> On Fri, Sep 26, 2008 at 04:36:41PM -0700, Arjan van de Ven wrote: > > A common thing in many PCI drivers is to ioremap() an entire bar. > > This is a slightly fragile thing right now, needing both an address > > and a size, and many driver writers do.. various things there. > > > > This patch introduces an ioremap_pcibar() function taking just a > > PCI device struct and the bar number as arguments, and figures this > > all out itself, in one place. In addition, we can add various > > sanity checks to this function (the patch already checks to make > > sure that the bar in question really is a MEM bar; few to no > > drivers do that sort of thing). > > So we already have a pci_iomap() which takes a 'max' argument. If you > make 'max' -1, don't you get this same behaviour?
there are many ways to map a bar... I'm just arguing for providing a really simple, hard-to-get-wrong, one which only takes a device and a bar number. The goal of my patch isn't to introduce new functionality per se (although having the ability to add checks is nice and welcome), it's mostly to provide a simple, hard-to-get-wrong interface. Less chance to get it wrong -> less hard to diagnose bugs.
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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