Commit c5d66587 authored by Ilya Lipnitskiy's avatar Ilya Lipnitskiy Committed by David S. Miller
Browse files

net: ethernet: mediatek: ppe: fix busy wait loop 



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: ba37b7ca ("net: ethernet: mtk_eth_soc: add support for initializing the PPE")
Signed-off-by: default avatarIlya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Cc: Felix Fietkau <nbd@nbd.name>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c133acf3

drivers/net/ethernet/mediatek/mtk_ppe.c

+9 −11
Original line number Diff line number Diff line
@@ -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);



	if (ret)

		dev_err(ppe->dev, "PPE table busy");



	return -ETIMEDOUT;

	return ret;

}



static void mtk_ppe_cache_clear(struct mtk_ppe *ppe)

drivers/net/ethernet/mediatek/mtk_ppe.h

+1 −0
Original line number Diff line number Diff line
@@ -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)