From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755357Ab3KTU5Q (ORCPT ); Wed, 20 Nov 2013 15:57:16 -0500 Received: from mail-ea0-f172.google.com ([209.85.215.172]:35296 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755207Ab3KTU5M (ORCPT ); Wed, 20 Nov 2013 15:57:12 -0500 Message-ID: <528D2224.9090106@gmail.com> Date: Wed, 20 Nov 2013 21:57:08 +0100 From: Sebastian Hesselbarth User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 To: Florian Fainelli CC: "David S. Miller" , netdev , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH RFC v1 7/7] net: cpsw: resume/suspend PHY on port start/stop References: <1384978913-8052-1-git-send-email-sebastian.hesselbarth@gmail.com> <1384978913-8052-8-git-send-email-sebastian.hesselbarth@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/2013 09:48 PM, Florian Fainelli wrote: > 2013/11/20 Sebastian Hesselbarth : >> Network PHYs consume a noticable amount of power. This adds phy_resume >> on slave_open and phy_suspend on slave_stop to save this power if the >> port is down anyway. >> >> Signed-off-by: Sebastian Hesselbarth >> --- >> Cc: David S. Miller >> Cc: netdev@vger.kernel.org >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-kernel@vger.kernel.org >> --- >> drivers/net/ethernet/ti/cpsw.c | 2 ++ >> 1 files changed, 2 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c >> index 90d41d2..f1dc54f 100644 >> --- a/drivers/net/ethernet/ti/cpsw.c >> +++ b/drivers/net/ethernet/ti/cpsw.c >> @@ -1013,6 +1013,7 @@ static void cpsw_slave_open(struct cpsw_slave *slave, struct cpsw_priv *priv) >> } else { >> dev_info(priv->dev, "phy found : id is : 0x%x\n", >> slave->phy->phy_id); >> + phy_resume(slave->phy); >> phy_start(slave->phy); > > Cannot phy_start() figure this out for us based on the internal PHY > device state machine? Yeah, as I said in the cover letter, I started with mv643xx_eth which is not using phy_start/stop as it probably should be. As soon as I looked at mvneta/cpsw, I also came to the conclusion that phy_suspend/resume should be hidden in phy_start/stop. > I would imagine that you would want to call phy_suspend/resume from an > Ethernet driver's PM suspend/resume callbacks to make sure that the > PHY also enters a low power mode, but I do not want to have to > remember that I need to call phy_resume before phy_start for instance. > As of today we have PHY_HALTED/PHY_RESUMING, and I think we certainly > need at least a PHY_SUSPENDED state to help us with that. > >> >> /* Configure GMII_SEL register */ >> @@ -1081,6 +1082,7 @@ static void cpsw_slave_stop(struct cpsw_slave *slave, struct cpsw_priv *priv) >> if (!slave->phy) >> return; >> phy_stop(slave->phy); >> + phy_suspend(slave->phy); > > Same here, why is not that hidden in phy_stop? If there is any fear > that this breaks setups where WoL is used or such, we could add a new > argument to phy_connect() and friends which says whether it is okay to > auto-suspend the PHY upon PHY_stop > >> phy_disconnect(slave->phy); >> slave->phy = NULL; >> } >> -- >> 1.7.2.5 >> >> -- >> 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/ > > >