Re: [PATCH] pci: print out DMA mask info

From: FUJITA Tomonori
Date: Thu Oct 09 2008 - 23:02:00 EST


On Fri, 10 Oct 2008 11:40:51 +0900
FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote:

> On Thu, 09 Oct 2008 14:27:33 -0700
> Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>
> > Grant Grundler wrote:
> > > On Wed, Oct 08, 2008 at 04:02:23PM -0700, Yinghai Lu wrote:
> > >> so can find out what is DMA mask is used for pci devices in addition to
> > >> default setting.
> > >
> > > I like the idea. I don't like the additional boot time output.
> > >
> > > But I'm thinking this could be an option to lspci.
> > > lspci already knows about the /sys tree. Can PCI export the two masks
> > > (dma_mask and dma_consistent_mask) and something like "lspci -td"
> > > would dump those in a nice way?
> > >
> > in boot log, it could link with driver, pci info...
> > >
> > >> got:
> > >> aacraid 0000:86:00.0: using 32bit DMA mask
> > >> aacraid 0000:86:00.0: using 32bit consistent DMA mask
> > >> aacraid 0000:86:00.0: using 64bit DMA mask
> > >> aacraid 0000:86:00.0: using 64bit consistent DMA mask
> >
> > and aacraid do 32bit at first then 64bit...
> >
> > so put that in boot message could be useful too.
>
> IIRC, aacraid uses 32bit dma_mask at startup then it executes a
> special command to get dma information from the card, and sets proper
> dma_mask. So the above message is not wrong for aacraid, I think.

Oh, what you wanted to say is, "pci uses 32bit dma_mask and
dma_consistent_mask by default so aacraid doesn't need to set dma_mask
and dma_consistent_mask at startup", then it's true. You can remove
it. But it's just harmless unnecessary code.

But again, I don't think this is a good reason to print such dma
information for everyone at boot time.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/