From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
To: Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
Sean Wang <sean.wang@mediatek.com>,
Mark Lee <Mark-MC.Lee@mediatek.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org
Cc: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Subject: [PATCH net-next 05/14] net: ethernet: mtk_eth_soc: reduce MDIO bus access latency
Date: Wed, 21 Apr 2021 21:09:05 -0700 [thread overview]
Message-ID: <20210422040914.47788-6-ilya.lipnitskiy@gmail.com> (raw)
In-Reply-To: <20210422040914.47788-1-ilya.lipnitskiy@gmail.com>
From: Felix Fietkau <nbd@nbd.name>
usleep_range often ends up sleeping much longer than the 10-20us provided
as a range here. This causes significant latency in mdio bus acceses,
which easily adds multiple seconds to the boot time on MT7621 when polling
DSA slave ports.
Use udelay via readx_poll_timeout_atomic, since the MDIO access does not
take much time
Signed-off-by: Felix Fietkau <nbd@nbd.name>
[Ilya: use readx_poll_timeout_atomic instead of cond_resched]
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 18 ++++++++----------
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 2 +-
2 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 5cf64de3ddf8..a3958e99a29f 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -79,18 +79,16 @@ static u32 mtk_m32(struct mtk_eth *eth, u32 mask, u32 set, unsigned reg)
static int mtk_mdio_busy_wait(struct mtk_eth *eth)
{
- unsigned long t_start = jiffies;
+ int ret;
+ u32 val;
- while (1) {
- if (!(mtk_r32(eth, MTK_PHY_IAC) & PHY_IAC_ACCESS))
- return 0;
- if (time_after(jiffies, t_start + PHY_IAC_TIMEOUT))
- break;
- usleep_range(10, 20);
- }
+ ret = readx_poll_timeout_atomic(__raw_readl, eth->base + MTK_PHY_IAC,
+ val, !(val & PHY_IAC_ACCESS),
+ 5, PHY_IAC_TIMEOUT_US);
+ if (ret)
+ dev_err(eth->dev, "mdio: MDIO timeout\n");
- dev_err(eth->dev, "mdio: MDIO timeout\n");
- return -1;
+ return ret;
}
static u32 _mtk_mdio_write(struct mtk_eth *eth, u32 phy_addr,
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 875e67b41561..989342a7ae4a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -327,7 +327,7 @@
#define PHY_IAC_START BIT(16)
#define PHY_IAC_ADDR_SHIFT 20
#define PHY_IAC_REG_SHIFT 25
-#define PHY_IAC_TIMEOUT HZ
+#define PHY_IAC_TIMEOUT_US 1000000
#define MTK_MAC_MISC 0x1000c
#define MTK_MUX_TO_ESW BIT(0)
--
2.31.1
next prev parent reply other threads:[~2021-04-22 4:09 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 4:09 [PATCH net-next 00/14] mtk_eth_soc: fixes and performance improvements Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 01/14] net: ethernet: mtk_eth_soc: fix RX VLAN offload Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 02/14] net: ethernet: mtk_eth_soc: unmap RX data before calling build_skb Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 03/14] net: ethernet: mtk_eth_soc: fix build_skb cleanup Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 04/14] net: ethernet: mtk_eth_soc: use napi_consume_skb Ilya Lipnitskiy
2021-04-22 4:09 ` Ilya Lipnitskiy [this message]
2021-04-22 12:18 ` [PATCH net-next 05/14] net: ethernet: mtk_eth_soc: reduce MDIO bus access latency Andrew Lunn
2021-04-22 12:33 ` Felix Fietkau
2021-04-23 4:16 ` Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 06/14] net: ethernet: mtk_eth_soc: remove unnecessary TX queue stops Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 07/14] net: ethernet: mtk_eth_soc: use larger burst size for QDMA TX Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 08/14] net: ethernet: mtk_eth_soc: increase DMA ring sizes Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 09/14] net: ethernet: mtk_eth_soc: implement dynamic interrupt moderation Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 10/14] net: ethernet: mtk_eth_soc: cache HW pointer of last freed TX descriptor Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 11/14] net: ethernet: mtk_eth_soc: only read the full RX descriptor if DMA is done Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 12/14] net: ethernet: mtk_eth_soc: reduce unnecessary interrupts Ilya Lipnitskiy
2021-04-22 16:26 ` Jakub Kicinski
2021-04-23 4:20 ` Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 13/14] net: ethernet: mtk_eth_soc: set PPE flow hash as skb hash if present Ilya Lipnitskiy
2021-04-22 4:09 ` [PATCH net-next 14/14] net: ethernet: mtk_eth_soc: use iopoll.h macro for DMA init Ilya Lipnitskiy
2021-04-22 12:20 ` Andrew Lunn
2021-04-22 12:23 ` [PATCH net-next 00/14] mtk_eth_soc: fixes and performance improvements Andrew Lunn
2021-04-23 4:18 ` Ilya Lipnitskiy
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