Re: [PATCH 2/2] scsi: Use new __dma_buffer to align sense buffer in scsi_cmnd

From: Thomas Bogendoerfer
Date: Fri Dec 21 2007 - 08:45:14 EST


On Fri, Dec 21, 2007 at 06:16:41AM -0700, Matthew Wilcox wrote:
> On Fri, Dec 21, 2007 at 10:33:26AM +0000, Alan Cox wrote:
> > On Fri, 21 Dec 2007 13:30:08 +1100
> > Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > > The sense buffer ins scsi_cmnd can nowadays be DMA'ed into directly
> > > by some low level drivers (that typically happens with USB mass
> > > storage).
> >
> > Should that not be fixed in USB storage by using pci_alloc_coherent on the
> > PCI device of the hub not peeing directly into kernel space ?
>
> That's what I said, but Ben seems fixated on this particular fix.

there are SCSI host drivers, which also DMA to the sense buffer like
sgiwd93.c for example.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea. [ RFC1925, 2.3 ]
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