[Nouveau] kernel spew from nouveau/ swiotlb

[Mike Galbraith]

On Thu, 2018-05-10 at 11:10 +0200, Mike Galbraith wrote:
> Greetings,
> 
> When box is earning its keep, nouveau/swiotlb grumble.. a LOT.  The
> below is from master.today.
> 
> [12594.640959] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12594.693000] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12594.713787] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12594.743413] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12594.796740] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12607.000774] swiotlb_tbl_map_single: 54 callbacks suppressed
> [12607.000776] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12607.347941] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> [12608.677038] nouveau 0000:01:00.0: swiotlb buffer is full (sz: 2097152 bytes)
> homer:/novell/ssh # dmesg|grep 'swiotlb buffer is full'|wc -l
> 2052
> homer:/novell/ssh # dmesg|grep 'callbacks suppressed'|wc -l
> 171
> 
> lib/swiotlb.c:
>  573 not_found:
>  574         spin_unlock_irqrestore(&io_tlb_lock, flags);
>  575         if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
>  576                 dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);
> 
> Does nouveau perhaps want one of those DMA_ATTR_NO_WARN thingies?

Or should ttm perhaps always use the one on hand?  (seems to work)

---
 drivers/gpu/drm/ttm/ttm_page_alloc_dma.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -342,7 +342,7 @@ static struct dma_page *__ttm_dma_alloc_
 	if (!d_page)
 		return NULL;
 
-	if (pool->type & IS_HUGE)
+	if (1 || pool->type & IS_HUGE)
 		attrs = DMA_ATTR_NO_WARN;
 
 	vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,