Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-25 Thread Stefan Richter
On 14 Jan, James Bottomley wrote: > The block layer currently provides sector (512) byte alignment > guarantees. However, there has been talk in SCSI of reducing that to > word (4) since that's what most intelligent PCI controllers can cope > with. If you have any alignment constraints, they shou

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-15 Thread James Bottomley
On Mon, 2007-01-15 at 21:02 +0100, Stefan Richter wrote: > > By the way, is there a way to ask the SCSI stack to limit the size of > > the entries in the scatterlist to 64k? This would greatly simplify > > the conversion to SBP-2 page tables, since this is the maximum size > > these can hold. > >

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-15 Thread Stefan Richter
On 15 Jan, Kristian Høgsberg wrote: > On 1/14/07, Stefan Richter <[EMAIL PROTECTED]> wrote: >> OK, thanks. I will keep the explicit setting of the mask then. >> I actually think that everything should work just fine with 4 bytes >> alignment, but the SBP-2 spec mentiones 8 bytes alignment for the S

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-15 Thread Mike Christie
Kristian Høgsberg wrote: > On 1/14/07, Stefan Richter <[EMAIL PROTECTED]> wrote: >> On 14 Jan, James Bottomley wrote: >> > The block layer currently provides sector (512) byte alignment >> > guarantees. However, there has been talk in SCSI of reducing that to >> > word (4) since that's what most i

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-15 Thread Kristian Høgsberg
On 1/14/07, Stefan Richter <[EMAIL PROTECTED]> wrote: On 14 Jan, James Bottomley wrote: > The block layer currently provides sector (512) byte alignment > guarantees. However, there has been talk in SCSI of reducing that to > word (4) since that's what most intelligent PCI controllers can cope >

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-14 Thread Stefan Richter
On 14 Jan, James Bottomley wrote: > The block layer currently provides sector (512) byte alignment > guarantees. However, there has been talk in SCSI of reducing that to > word (4) since that's what most intelligent PCI controllers can cope > with. If you have any alignment constraints, they shou

Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-14 Thread James Bottomley
On Sun, 2007-01-14 at 19:45 +0100, Stefan Richter wrote: > I wonder, do we need this call to blk_queue_dma_alignment() at all? > Does the block layer perhaps provide sufficient alignment guarantees? The block layer currently provides sector (512) byte alignment guarantees. However, there has been

[PATCH] ieee1394: sbp2: lower block queue alignment requirement

2007-01-14 Thread Stefan Richter
The old setting seems to be copy & paste from usb-storage. Signed-off-by: Stefan Richter <[EMAIL PROTECTED]> --- I wonder, do we need this call to blk_queue_dma_alignment() at all? Does the block layer perhaps provide sufficient alignment guarantees? Index: linux/drivers/ieee1394/sbp2.c ===