Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755327Ab3JHPUF (ORCPT ); Tue, 8 Oct 2013 11:20:05 -0400 Received: from mail.abilis.ch ([195.70.19.74]:20250 "EHLO mail.abilis.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753013Ab3JHPUD (ORCPT ); Tue, 8 Oct 2013 11:20:03 -0400 X-Greylist: delayed 1070 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Oct 2013 11:20:02 EDT From: Romain Baeriswyl To: Giuseppe Cavallaro Cc: "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Romain Baeriswyl Subject: [RFC] net: stmmac: keep RXC running in LPI mode to avoid system overload Date: Tue, 8 Oct 2013 17:06:35 +0200 Message-Id: <1381244795-3922-1-git-send-email-romainba@abilis.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1902 Lines: 49 In order to avoid system overload, the clock RXC from the Phy should not be stopped when in LPI mode. With the RTL8211E PHY which support EEE mode and with Apple Airport Extreme that supports it also, the kernel get frozen as soon as some Ethernet transfers are on-going. System seems to be overloaded with too many interrupts. The 'top' command reports often around ~80% irq. By letting the RXC clock running even in LPI mode as proposed below, the issue seems solved. Is it the right way to proceed? What is the power impact to not stop RXC in LPI mode? --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index e9eab29..d40d26b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -314,7 +314,8 @@ bool stmmac_eee_init(struct stmmac_priv *priv) /* MAC core supports the EEE feature. */ if (priv->dma_cap.eee) { /* Check if the PHY supports EEE */ - if (phy_init_eee(priv->phydev, 1)) + /* Keeps RXC running in LPI mode to avoid stability issue */ + if (phy_init_eee(priv->phydev, 0)) goto out; if (!priv->eee_active) { @@ -770,7 +771,8 @@ static void stmmac_adjust_link(struct net_device *dev) /* At this stage, it could be needed to setup the EEE or adjust some * MAC related HW registers. */ - priv->eee_enabled = stmmac_eee_init(priv); + if (new_state) + priv->eee_enabled = stmmac_eee_init(priv); spin_unlock_irqrestore(&priv->lock, flags); } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/