RE: [Linux-ia64] RE: DMA memory limitation?

From: White, Charles <>
Date: 2001-07-10 01:33:24
Yes, I thought about doing it that way, and it COULD be done, but right now
the driver allocates command buffer for IOCTLs as needed.  

So the pci_dev set to NULL allows to continue to do that... 

		-----Original Message-----
		From: []
		Sent:	Monday, July 09, 2001 10:20 AM
		To:	White, Charles
		Subject:	RE: [Linux-ia64] RE: DMA memory limitation?

		> My device has the limitation that the command buffers I
		> must be in 32
		> bit space, but the IO can be in 64 bit.  But there is only

		> ONE dma_mask for the device.

		Ahh, yes.  The AMI MegaRAID driver/controllers have the same
		megaraid solved it as:

		pci_find_device() finds their device, they get a pci_dev
back which has a
		32-bit dma_mask.
		pci_alloc_consistent() the mailbox (this must be in 32-bit
		if it's a 64-bit-capable controller, set pci_dev->dma_mask =
		pci_alloc_consistent() the command buffers and
scatter-gather lists (these
		can be in 64-bit space).

		Could something similar work for you?


		Matt Domsch
		Sr. Software Engineer
		Dell Linux Solutions
		#2 Linux Server provider with 17% in the US and 14%
Worldwide (IDC)!
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Received on Mon Jul 09 08:34:10 2001

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