lkml.org 
[lkml]   [2008]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] pci: introduce users of ioremap_pcibar()
On Mon, 29 Sep 2008 01:26:43 -0600
Grant Grundler <grundler@parisc-linux.org> wrote:
>
> Alternatively, the ioremap_pcibar() code needs to check for
> cacheable attribute and DTRT.

we should make it "if prefetchable, UC-, if not, hard UC", yes.

> > - core->lmmio = ioremap(pci_resource_start(pci, 0),
> > - pci_resource_len(pci, 0));
> > + core->lmmio = ioremap_pcibar(pci, 0);
>
> Is there any easy way to tell if the device driver should be using
> uncached mappings vs cacheable mappings?
> (Just from looking at the source code)
>
> This patch changes that behavior of the device driver so it uses
> uncacheable instead of cacheable mappings. This is the only thing
> I'm uncertain about for this patch.

ioremap() also is uncachable today.


>
> And I have a second issue less important issue.
> What is the result of ioremap_pcibar(pci, 1) when BAR0 is a 64-bit
> bar? Given the name, I expect to call "ioremap_pcibar(pci,2)" to get
> the desired result. Maybe just document how to handle this correctly
> in Documentation/pci.txt would be sufficient.

we should detect this and DTRT inside the implementation, not in the
drivers.

--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org


\
 
 \ /
  Last update: 2008-09-29 15:45    [W:0.922 / U:3.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site