lkml.org 
[lkml]   [2005]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: MSI and driver APIs
From
From: Roland Dreier <rdreier@cisco.com>
Date: Thu, 15 Dec 2005 13:18:04 -0800

> Benjamin> I'm tempted to leave them enabled and only disable them
> Benjamin> when request_irq() is done on the legacy INTx... Does
> Benjamin> anybody see a problem with this approach ?
>
> You might run into trouble on hardware (think tg3 or its ilk again)
> where you might have to do something beyond disabling MSI in the PCI
> header to switch the chip out of MSI mode.

I think because of kinds of cases and other issues, going with
MSI by default is a non-starter.

Perhaps a better approach is to use a flag in the pci_driver_struct or
similar that says "you can have MSI enabled by default". And
gradually convert drivers over which we know will handle it properly.

Doing some tom foolery with request_irq() sounds like a half-baked
idea at best. The biggest argument against that is that this is
not a PCI interface, so expecting it to have PCI side effects is
really asking for trouble.
-
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: 2005-12-15 22:46    [W:0.528 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site