lkml.org 
[lkml]   [2005]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH] PCI: remove access to pci_[enable|disable]_msi() for drivers
On Mon, Jun 06, 2005 at 06:09:11PM -0700, Andrew Vasquez wrote:
> On Mon, 06 Jun 2005, Greg KH wrote:
>
> >
> > Ok, as it seems there is a bit of confusion, here's real code that
> > should help explain what I am proposing. This works on my desktop, but
> > I don't think it supports MSI :)
> >
> > I'll go dig out an old 4-way AMD box that has MSI to see if this still
> > works properly, but comments are welcome.
>
>
> Thanks for posting some sample code. Some comments though:
>
> * What if the driver writer does not want MSI enabled for their
> hardware (even though there is an MSI capabilities entry)? Reasons
> include: overhead involved in initiating the MSI; no support in some
> versions of firmware (QLogic hardware).

Yes, a very good point. I guess I should keep the pci_enable_msi() and
pci_disable_msi() functions exported for this reason.

> * A device (notably, our 4gb PCIe fibre-channel products) can support
> both MSI and MSI-X. Since the driver has no way of 'disabling' MSI,
> how would it enable MSI-X?

Agreed, let me respin the patches again, because I think I got the logic
wrong on some of these drivers because of this...

thanks,

greg k-h
-
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: 2005-06-07 07:20    [W:1.722 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site