2022-01-24 10:07:25

by Jisheng Zhang

Subject: [PATCH] net: stmmac: reduce unnecessary wakeups from eee sw timer

Currently, on EEE capable platforms, if EEE SW timer is used, the SW
timer cause 1 wakeup/s even if the TX has successfully entered EEE.
Remove this unnecessary wakeup by only calling mod_timer() if we
haven't successfully entered EEE.

Signed-off-by: Jisheng Zhang <[email protected]>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 92a9b0b226b1..f1246df143da 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -402,7 +402,7 @@ static void stmmac_lpi_entry_timer_config(struct stmmac_priv *priv, bool en)
* Description: this function is to verify and enter in LPI mode in case of
* EEE.
*/
-static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
+static int stmmac_enable_eee_mode(struct stmmac_priv *priv)
{
u32 tx_cnt = priv->plat->tx_queues_to_use;
u32 queue;
@@ -412,13 +412,14 @@ static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];

if (tx_q->dirty_tx != tx_q->cur_tx)
- return; /* still unfinished work */
+ return -EBUSY; /* still unfinished work */
}

/* Check and enter in LPI mode */
if (!priv->tx_path_in_lpi_mode)
stmmac_set_eee_mode(priv, priv->hw,
priv->plat->en_tx_lpi_clockgating);
+ return 0;
}

/**
@@ -450,8 +451,8 @@ static void stmmac_eee_ctrl_timer(struct timer_list *t)
{
struct stmmac_priv *priv = from_timer(priv, t, eee_ctrl_timer);

- stmmac_enable_eee_mode(priv);
- mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(priv->tx_lpi_timer));
+ if (stmmac_enable_eee_mode(priv))
+ mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(priv->tx_lpi_timer));
}

/**
@@ -2647,8 +2648,8 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)

if (priv->eee_enabled && !priv->tx_path_in_lpi_mode &&
priv->eee_sw_timer_en) {
- stmmac_enable_eee_mode(priv);
- mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(priv->tx_lpi_timer));
+ if (stmmac_enable_eee_mode(priv))
+ mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(priv->tx_lpi_timer));
}

/* We still have pending packets, let's call for a new scheduling */
--
2.34.1

2022-01-26 01:19:56

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: stmmac: reduce unnecessary wakeups from eee sw timer

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Sun, 23 Jan 2022 23:54:58 +0800 you wrote:
> Currently, on EEE capable platforms, if EEE SW timer is used, the SW
> timer cause 1 wakeup/s even if the TX has successfully entered EEE.
> Remove this unnecessary wakeup by only calling mod_timer() if we
> haven't successfully entered EEE.
>
> Signed-off-by: Jisheng Zhang <[email protected]>
>
> [...]

Here is the summary with links:
- net: stmmac: reduce unnecessary wakeups from eee sw timer
https://git.kernel.org/netdev/net/c/c74ead223deb

You are awesome, thank you!
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