diff mbox series

[net-next,v3] net: ethernet: mediatek: ppe: fix busy wait loop

Message ID 20210416003747.340041-1-ilya.lipnitskiy@gmail.com (mailing list archive)
State Accepted
Commit c5d66587b8900201e1530b7c18d41e87bd5812f4
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v3] net: ethernet: mediatek: ppe: fix busy wait loop | expand

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Commit Message

Ilya Lipnitskiy April 16, 2021, 12:37 a.m. UTC
The intention is for the loop to timeout if the body does not succeed.
The current logic calls time_is_before_jiffies(timeout) which is false
until after the timeout, so the loop body never executes.

Fix by using readl_poll_timeout as a more standard and less error-prone
solution.

Fixes: ba37b7caf1ed ("net: ethernet: mtk_eth_soc: add support for initializing the PPE")
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Cc: Felix Fietkau <nbd@nbd.name>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
v2:
  - Use readl_poll_timeout as suggested by Andrew Lunn
v3:
  - Remove unused #include's

 drivers/net/ethernet/mediatek/mtk_ppe.c | 20 +++++++++-----------
 drivers/net/ethernet/mediatek/mtk_ppe.h |  1 +
 2 files changed, 10 insertions(+), 11 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org April 16, 2021, 10:30 p.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Thu, 15 Apr 2021 17:37:48 -0700 you wrote:
> The intention is for the loop to timeout if the body does not succeed.
> The current logic calls time_is_before_jiffies(timeout) which is false
> until after the timeout, so the loop body never executes.
> 
> Fix by using readl_poll_timeout as a more standard and less error-prone
> solution.
> 
> [...]

Here is the summary with links:
  - [net-next,v3] net: ethernet: mediatek: ppe: fix busy wait loop
    https://git.kernel.org/netdev/net-next/c/c5d66587b890

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 71e1ccea6e72..3ad10c793308 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -2,9 +2,8 @@ 
 /* Copyright (C) 2020 Felix Fietkau <nbd@nbd.name> */
 
 #include <linux/kernel.h>
-#include <linux/jiffies.h>
-#include <linux/delay.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/etherdevice.h>
 #include <linux/platform_device.h>
 #include "mtk_ppe.h"
@@ -44,18 +43,17 @@  static u32 ppe_clear(struct mtk_ppe *ppe, u32 reg, u32 val)
 
 static int mtk_ppe_wait_busy(struct mtk_ppe *ppe)
 {
-	unsigned long timeout = jiffies + HZ;
-
-	while (time_is_before_jiffies(timeout)) {
-		if (!(ppe_r32(ppe, MTK_PPE_GLO_CFG) & MTK_PPE_GLO_CFG_BUSY))
-			return 0;
+	int ret;
+	u32 val;
 
-		usleep_range(10, 20);
-	}
+	ret = readl_poll_timeout(ppe->base + MTK_PPE_GLO_CFG, val,
+				 !(val & MTK_PPE_GLO_CFG_BUSY),
+				 20, MTK_PPE_WAIT_TIMEOUT_US);
 
-	dev_err(ppe->dev, "PPE table busy");
+	if (ret)
+		dev_err(ppe->dev, "PPE table busy");
 
-	return -ETIMEDOUT;
+	return ret;
 }
 
 static void mtk_ppe_cache_clear(struct mtk_ppe *ppe)
diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.h b/drivers/net/ethernet/mediatek/mtk_ppe.h
index 51bd5e75bbbd..242fb8f2ae65 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.h
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.h
@@ -12,6 +12,7 @@ 
 #define MTK_PPE_ENTRIES_SHIFT		3
 #define MTK_PPE_ENTRIES			(1024 << MTK_PPE_ENTRIES_SHIFT)
 #define MTK_PPE_HASH_MASK		(MTK_PPE_ENTRIES - 1)
+#define MTK_PPE_WAIT_TIMEOUT_US		1000000
 
 #define MTK_FOE_IB1_UNBIND_TIMESTAMP	GENMASK(7, 0)
 #define MTK_FOE_IB1_UNBIND_PACKETS	GENMASK(23, 8)