[PATCH AUTOSEL 4.14 085/103] MIPS: lantiq: Do not enable IRQs in dma open

From: Sasha Levin
Date: Fri Nov 08 2019 - 06:45:27 EST


From: Hauke Mehrtens <hauke@xxxxxxxxxx>

[ 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 <hauke@xxxxxxxxxx>
Acked-by: Paul Burton <paul.burton@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 805b3a6ab2d60..dcc16d8de8c37 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 afc8100694405..c978a857a25c2 100644
--- a/drivers/net/ethernet/lantiq_etop.c
+++ b/drivers/net/ethernet/lantiq_etop.c
@@ -438,6 +438,7 @@ 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