Subject: Re: Parallel ATA with libata status with the patches I'm working on
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-kernel@vger.kernel.org
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Date: Sun, 06 Nov 2005 20:41:31 +0000
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On Sad, 2005-11-05 at 08:50 +1100, Benjamin Herrenschmidt wrote:
> OK, but my question why, what is the reason why we need IRQ mask ? Some
> old non-PCI controllers can't grok un-related ISA IO cycles during a
> FIFO read/write ? I suppose those would be broken on SMP too (though I
> suspect then that those don't exist as SMP machines then :)

There are PCI controllers that are hosed too. They incorrectly handle
the situation where the PCI fifo empties/fills and the controller should
indicate to the drive to stall the transfer. The chipsets I know that
are afflicted with this are all uniprocessor mainboard devices.

Alan

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