Subject: [PATCH AUTOSEL 4.19 171/205] MIPS: lantiq: Do not enable IRQs in dma open

From: Sasha Levin <[email-masked]>
Date: Fri, 8 Nov 2019 06:37:18 -0500

From: Hauke Mehrtens <[email-masked]>

[ Upstream commit cc973aecf0b0541918c5ecabe6c90d1f709b5f89 ]

When a DMA channel is opened the IRQ should not get activated
automatically, this allows it to pull data out manually without the help
of interrupts. This is needed for a workaround in the vrx200 Ethernet
driver.

Signed-off-by: Hauke Mehrtens <[email-masked]>
Acked-by: Paul Burton <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 arch/mips/lantiq/xway/dma.c        | 1 -
 drivers/net/ethernet/lantiq_etop.c | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c
index 664f2f7f55c1c..982859f2b2a38 100644
--- a/arch/mips/lantiq/xway/dma.c
+++ b/arch/mips/lantiq/xway/dma.c
@@ -106,7 +106,6 @@ ltq_dma_open(struct ltq_dma_channel *ch)
 	spin_lock_irqsave(&ltq_dma_lock, flag);
 	ltq_dma_w32(ch->nr, LTQ_DMA_CS);
 	ltq_dma_w32_mask(0, DMA_CHAN_ON, LTQ_DMA_CCTRL);
-	ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
 	spin_unlock_irqrestore(&ltq_dma_lock, flag);
 }
 EXPORT_SYMBOL_GPL(ltq_dma_open);
diff --git a/drivers/net/ethernet/lantiq_etop.c b/drivers/net/ethernet/lantiq_etop.c
index e08301d833e2e..379db19a303c8 100644
--- a/drivers/net/ethernet/lantiq_etop.c
+++ b/drivers/net/ethernet/lantiq_etop.c
@@ -439,6 +439,7 @@ ltq_etop_open(struct net_device *dev)
 		if (!IS_TX(i) && (!IS_RX(i)))
 			continue;
 		ltq_dma_open(&ch->dma);
+		ltq_dma_enable_irq(&ch->dma);
 		napi_enable(&ch->napi);
 	}
 	phy_start(dev->phydev);
-- 
2.20.1