I'm ok with enabling this for people that just want to use DMA and not RAID.
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 */ >
