[PATCH v2 2/4] mt76: add unlikely() for dma_mapping_error() check

From: Ryder Lee
Date: Mon Apr 01 2019 - 02:56:37 EST


In the tx/rx fastpath, the funciton dma_map_single() rarely fails.
This adds unlikely() optimization to this error check conditional.

Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/dma.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 8a4b935..6f3ef09 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -272,7 +272,7 @@

addr = dma_map_single(dev->dev, skb->data, skb->len,
DMA_TO_DEVICE);
- if (dma_mapping_error(dev->dev, addr))
+ if (unlikely(dma_mapping_error(dev->dev, addr)))
return -ENOMEM;

buf.addr = addr;
@@ -315,7 +315,7 @@

len = skb_headlen(skb);
addr = dma_map_single(dev->dev, skb->data, len, DMA_TO_DEVICE);
- if (dma_mapping_error(dev->dev, addr))
+ if (unlikely(dma_mapping_error(dev->dev, addr)))
goto free;

tx_info.buf[n].addr = t->dma_addr;
@@ -329,7 +329,7 @@

addr = dma_map_single(dev->dev, iter->data, iter->len,
DMA_TO_DEVICE);
- if (dma_mapping_error(dev->dev, addr))
+ if (unlikely(dma_mapping_error(dev->dev, addr)))
goto unmap;

tx_info.buf[n].addr = addr;
@@ -386,7 +386,7 @@
break;

addr = dma_map_single(dev->dev, buf, len, DMA_FROM_DEVICE);
- if (dma_mapping_error(dev->dev, addr)) {
+ if (unlikely(dma_mapping_error(dev->dev, addr))) {
skb_free_frag(buf);
break;
}
--
1.9.1