Re: struct page to 36 (or 64) bit bus address?

David S. Miller
2001-08-13T19:43:06Z

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From: Gérard Roudier <groudier@free.fr>
Date: Mon, 13 Aug 2001 21:07:50 +0200 (CEST)

That's the major problem if we ever want to preserve some ordering in the
queuing of SCSI IOs.

When DMA mapping operation fails, you simply "stop queueing". Queue
freezes and nothing new is executed.

DMA wakeup makes you start where you left off. I cannot see any
ordering constraints violated by this as a side effect. It is like a
"cork" for running scsi commands in the driver.

The purpose of the hypothetical kernel thread is to get out
of interrupt context if that is deemed necessary.

It may not be.

Later,
David S. Miller
davem@redhat.com
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