Re: [PATCH 2/2] Base pSeries PCIe support
From: Christoph Hellwig <hch@lst.de>
Date: 2006-04-12 04:05:16
From: Christoph Hellwig <hch@lst.de>
Date: 2006-04-12 04:05:16
On Fri, Mar 31, 2006 at 04:13:30PM -0600, Jake Moilanen wrote:
This patch hooks our current interrupt subsystem and sets up a single vector MSI as if it was a LSI. Multiple MSI vectors is coming in the future.
This is broken. Linux drivers expect MSI to be disabled on ->probe.
There's at least two reasons for that:
(1) Many devices that claim to implement MSI are actually broken in
more or less subtile ways. and thus must use traditition INTx pins.
(2) MSI defines relaxed semantics for dma synchronization. Silently
enabling MSI could cause subtile data corruption.