On Wed, Jul 31, 2013 at 03:14:07PM -0700, Jiang, Dave wrote: > I'm ok with enabling this for people that just want to use DMA and not > RAID.
I might be crazy, but I'd be in favor of disabling the RAID offload by default on non-Atom platforms. Thanks, Jon > > Acked-by: Dave Jiang <dave.ji...@intel.com> > > On Thu, 2013-08-01 at 00:05 +0200, Brice Goglin wrote: > > ioatdma: add ioat_raid_enabled module parameter > > > > Commit f26df1a1 added a 64-byte alignment requirement for legacy > > operations to work around a silicon errata when mixing legacy and > > RAID descriptors. > > Passing ioat_raid_enabled=0 now disables RAID offload entirely in > > the ioatdma driver so that legacy operations (memcpy, etc.) can > > work without alignment restrictions anymore. > > > > Signed-off-by: Brice Goglin <brice.gog...@inria.fr> > > --- > > drivers/dma/ioat/dma_v3.c | 9 +++++++-- > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > Index: b/drivers/dma/ioat/dma_v3.c > > =================================================================== > > --- a/drivers/dma/ioat/dma_v3.c 2013-07-31 23:06:24.163810000 +0200 > > +++ b/drivers/dma/ioat/dma_v3.c 2013-07-31 23:47:54.246719841 +0200 > > @@ -67,6 +67,11 @@ > > #include "dma.h" > > #include "dma_v2.h" > > > > +static int ioat_raid_enabled = 1; > > +module_param(ioat_raid_enabled, int, 0444); > > +MODULE_PARM_DESC(ioat_raid_enabled, > > + "control support of RAID offload (default: 1)"); > > + > > /* ioat hardware assumes at least two sources for raid operations */ > > #define src_cnt_to_sw(x) ((x) + 2) > > #define src_cnt_to_hw(x) ((x) - 2) > > @@ -1775,7 +1780,7 @@ int ioat3_dma_probe(struct ioatdma_devic > > dma->device_alloc_chan_resources = ioat2_alloc_chan_resources; > > dma->device_free_chan_resources = ioat2_free_chan_resources; > > > > - if (is_xeon_cb32(pdev)) > > + if (is_xeon_cb32(pdev) && ioat_raid_enabled) > > dma->copy_align = 6; > > > > dma_cap_set(DMA_INTERRUPT, dma->cap_mask); > > @@ -1783,7 +1788,7 @@ int ioat3_dma_probe(struct ioatdma_devic > > > > device->cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET); > > > > - if (is_bwd_noraid(pdev)) > > + if (!ioat_raid_enabled || is_bwd_noraid(pdev)) > > device->cap &= ~(IOAT_CAP_XOR | IOAT_CAP_PQ | > > IOAT_CAP_RAID16SS); > > > > /* dca is incompatible with raid operations */ > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
