From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: Re: [PATCH] net: stmmac: disable/enable ptp_ref_clk in suspend/resume flow Date: Thu, 10 Oct 2019 16:01:03 -0700 Message-ID: <20191010160103.63c3c0ed@cakuba.netronome.com> References: <20191009085649.6736-1-biao.huang@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191009085649.6736-1-biao.huang@mediatek.com> Sender: netdev-owner@vger.kernel.org To: Biao Huang Cc: davem@davemloft.net, Jose Abreu , andrew@lunn.ch, Giuseppe Cavallaro , Alexandre Torgue , Maxime Coquelin , Matthias Brugger , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, yt.shen@mediatek.com, jianguo.zhang@mediatek.com, boon.leong.ong@intel.com List-Id: linux-mediatek@lists.infradead.org On Wed, 9 Oct 2019 16:56:49 +0800, Biao Huang wrote: > disable ptp_ref_clk in suspend flow, and enable it in resume flow. > > Signed-off-by: Biao Huang > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index c7c9e5f162e6..b592aeecc3dd 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -4469,6 +4469,8 @@ int stmmac_suspend(struct device *dev) > stmmac_mac_set(priv, priv->ioaddr, false); > pinctrl_pm_select_sleep_state(priv->device); > /* Disable clock in case of PWM is off */ > + if (priv->plat->clk_ptp_ref) > + clk_disable_unprepare(priv->plat->clk_ptp_ref); I don't know much embedded, but it seems like this should perhaps just be clk_disable() without the unprepare? stmmac_hw_teardown() is called when driver is removed so it needs to unprepare as well. Please feel free to explain to me why this needs to be clk_disable_unprepare(), as I said - not an expert. Also - if this is a bug fix and you'd like to have it backported to older releases you need to add a Fixes tag. Thanks! > clk_disable(priv->plat->pclk); > clk_disable(priv->plat->stmmac_clk); > } > @@ -4535,6 +4537,8 @@ int stmmac_resume(struct device *dev) > /* enable the clk previously disabled */ > clk_enable(priv->plat->stmmac_clk); > clk_enable(priv->plat->pclk); > + if (priv->plat->clk_ptp_ref) > + clk_prepare_enable(priv->plat->clk_ptp_ref); > /* reset the phy so that it's ready */ > if (priv->mii) > stmmac_mdio_reset(priv->mii);