Messages in this thread | | | Date | Sat, 04 Aug 2007 11:14:04 -0600 | From | Robert Hancock <> | Subject | Re: [PATCH 2.6.22.y] ieee1394: revert "sbp2: enforce 32bit DMA mapping" |
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Stefan Richter wrote: > Date: Wed, 1 Aug 2007 20:30:36 +0200 (CEST) > From: Stefan Richter <stefanr@s5r6.in-berlin.de> > Subject: ieee1394: revert "sbp2: enforce 32bit DMA mapping" > > Revert commit 0555659d63c285ceb7ead3115532e1b71b0f27a7 from 2.6.22-rc1. > The dma_set_mask call somehow failed on a PowerMac G5, PPC64: > http://lkml.org/lkml/2007/8/1/344 > > Should there ever occur a DMA mapping beyond the physical DMA range, a > proper SBP-2 firmware will report transport errors. So let's leave it > at that.
Isn't this a rather poor workaround? All this means is that if we fail to set a 32-bit DMA mask, we're likely to blow up at runtime instead of at initialization time, when we get a DMA mapping over 4GB.
If setting 32-bit DMA mask fails on ppc64, that sounds like a problem with the DMA implementation on that architecture. There are enough cards out there that only support 32-bit DMA that this really needs to work..
> > Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> > Tested-by: Olaf Hering <olh@suse.de> > --- > Same as commit a9c2f18800753c82c45fc13b27bdc148849bdbb2. > > drivers/ieee1394/sbp2.c | 5 ----- > 1 file changed, 5 deletions(-) > > Index: linux-2.6.22/drivers/ieee1394/sbp2.c > =================================================================== > --- linux-2.6.22.orig/drivers/ieee1394/sbp2.c > +++ linux-2.6.22/drivers/ieee1394/sbp2.c > @@ -774,11 +774,6 @@ static struct sbp2_lu *sbp2_alloc_device > SBP2_ERR("failed to register lower 4GB address range"); > goto failed_alloc; > } > -#else > - if (dma_set_mask(hi->host->device.parent, DMA_32BIT_MASK)) { > - SBP2_ERR("failed to set 4GB DMA mask"); > - goto failed_alloc; > - } > #endif > } > >
-- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/
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