From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory CLEMENT Subject: Re: [patch v2 1/3] drivers: phy: Make NULL a valid phy reference Date: Mon, 03 Feb 2014 22:15:12 +0100 Message-ID: <52F006E0.5080903@free-electrons.com> References: <52EF6D38.4060200@ti.com> <1391450446-15580-1-git-send-email-andrew@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from top.free-electrons.com ([176.31.233.9]:53079 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750789AbaBCVPR (ORCPT ); Mon, 3 Feb 2014 16:15:17 -0500 In-Reply-To: <1391450446-15580-1-git-send-email-andrew@lunn.ch> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Andrew Lunn Cc: tj@kernel.org, kishon@ti.com, Jason Cooper , linux-ide@vger.kernel.org On 03/02/2014 19:00, Andrew Lunn wrote: > The common clock framework considers NULL a valid clock > reference. This makes handling optional clocks simple, in that if the > optional clock is not available, a NULL reference can be used in the > place of a real clock, simplifying the clock consumer. > > Extend this concept to the phy consumer API. A NULL can be passed to > the release calls, the phy_init() and phy_exit() calls, and > phy_power_on() and phy_power_off() and a NOP is performed. > Hi Andrew, I have tested these 3 patches on severals Armada 370/XP boards: - Mirabox - Armada 370 DB - OpenBlocks AX3 - Armada XP GP For all this boards without these series the kernel crash during boot on v3.14-rc1. With this series (and "ATA: SATA_MV: Add missing Kconfig select statememnt" patch), the kernel boot fine on all these boards. You can add my Tested-by: Gregory CLEMENT for the whole series. Thanks, Gregory > Signed-off-by: Andrew Lunn > --- > v2 > No change. > --- > Documentation/phy.txt | 6 ++++++ > drivers/phy/phy-core.c | 18 ++++++++++++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/Documentation/phy.txt b/Documentation/phy.txt > index 0103e4b15b0e..2e24b993e95f 100644 > --- a/Documentation/phy.txt > +++ b/Documentation/phy.txt > @@ -84,6 +84,12 @@ The only difference between the two APIs is that devm_phy_get associates the > device with the PHY using devres on successful PHY get. On driver detach, > release function is invoked on the the devres data and devres data is freed. > > +It should be noted that NULL is a valid phy reference. All phy > +consumer calls on the NULL phy become NOPs. That is the release calls, > +the phy_init() and phy_exit() calls, and phy_power_on() and > +phy_power_off() calls are all NOP when applied to a NULL phy. The NULL > +phy is useful in devices for handling optional phy devices. > + > 5. Releasing a reference to the PHY > > When the controller no longer needs the PHY, it has to release the reference > diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c > index 645c867c1257..56535253e50c 100644 > --- a/drivers/phy/phy-core.c > +++ b/drivers/phy/phy-core.c > @@ -162,6 +162,9 @@ int phy_init(struct phy *phy) > { > int ret; > > + if (!phy) > + return 0; > + > ret = phy_pm_runtime_get_sync(phy); > if (ret < 0 && ret != -ENOTSUPP) > return ret; > @@ -187,6 +190,9 @@ int phy_exit(struct phy *phy) > { > int ret; > > + if (!phy) > + return 0; > + > ret = phy_pm_runtime_get_sync(phy); > if (ret < 0 && ret != -ENOTSUPP) > return ret; > @@ -212,6 +218,9 @@ int phy_power_on(struct phy *phy) > { > int ret; > > + if (!phy) > + return 0; > + > ret = phy_pm_runtime_get_sync(phy); > if (ret < 0 && ret != -ENOTSUPP) > return ret; > @@ -240,6 +249,9 @@ int phy_power_off(struct phy *phy) > { > int ret; > > + if (!phy) > + return 0; > + > mutex_lock(&phy->mutex); > if (phy->power_count == 1 && phy->ops->power_off) { > ret = phy->ops->power_off(phy); > @@ -308,6 +320,9 @@ err0: > */ > void phy_put(struct phy *phy) > { > + if (!phy) > + return; > + > if (IS_ERR(phy)) > return; > > @@ -328,6 +343,9 @@ void devm_phy_put(struct device *dev, struct phy *phy) > { > int r; > > + if (!phy) > + return; > + > r = devres_destroy(dev, devm_phy_release, devm_phy_match, phy); > dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n"); > } > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com