lkml.org 
[lkml]   [2005]   [Jun]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: pci_enable_msi() for everyone?
On Fri, Jun 03, 2005 at 03:45:51PM -0700, Greg KH wrote:
> In talking with a few people about the MSI kernel code, they asked why
> we can't just do the pci_enable_msi() call for every pci device in the
> system (at somewhere like pci_enable_device() time or so). That would
> let all drivers and devices get the MSI functionality without changing
> their code, and probably make the api a whole lot simpler.

One complication is some drivers will want to register a different
IRQ handler depending on if MSI is enabled or not.
If MSI is enabled (and usable), then some MMIO reads can be omitted.
I've posted a patch for tg3 driver:
ftp://ftp.parisc-linux.org/patches/diff-2.6.10-tg3_MSI-03

(Just an example! It was not accepted because of buggy HW
though it worked great on the HW I have access to.)

drivers/infiniband/hw/mthca driver is another example.

> Now I know the e1000 driver would have to specifically disable MSI for
> some of their broken versions, and possibly some other drivers might
> need this, but the downside seems quite small.
>
> Or am I missing something pretty obvious here?

How can the driver know which IRQ handlers to register?

grant
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-06-04 03:31    [W:0.162 / U:0.016 seconds]
©2003-2011 Jasper Spaans. Advertise on this site