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From: andrew@lunn•ch (Andrew Lunn)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 07/12] hwrng: bcm2835-rng: Manage an optional clock
Date: Sat, 4 Nov 2017 20:37:31 +0100	[thread overview]
Message-ID: <20171104193731.GA751@lunn.ch> (raw)
In-Reply-To: <547786283.132202.1509819754396@email.1und1.de>

Hi Florian

> > >> +	/* Clock is optional on most platforms */
> > >> +	priv->clk = devm_clk_get(dev, NULL);
> > >> +	if (IS_ERR(priv->clk))
> > >> +		priv->clk = NULL;
> > > 
> > > at least in case of EPROBE_DEFERED this isn't the expected behavior. Maybe we should better trigger on non-existing clock?
> > 
> > Good point, so more like:
> > 
> > if (IS_ERR(priv->clk) && PTR_ERR(priv->clk) == -ENODEV)?
> 

> Unfortunately we need to return the error in all other cases. Please
> take a look at devm_usb_get_phy in dwc2 [1]. AFAIK we don't need to
> take care of ENXIO in our case.

A few subsystems have a get_optional() call, e.g.
devm_phy_optional_get(). It does not return an error when the phy is
not supposed to exist, but in all other cases, it does.

Maybe consider adding devm_clk_get_optional()?

      Andrew

  reply	other threads:[~2017-11-04 19:37 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02  1:03 [PATCH 00/12] bcm63xx-rng conversion to bcm2835-rng Florian Fainelli
2017-11-02  1:03 ` [PATCH 01/12] hwrng: bcm2835-rng: Obtain base register via resource Florian Fainelli
2017-11-02  1:03 ` [PATCH 02/12] hwrng: bcm2835-rng: Define a driver private context Florian Fainelli
2017-11-02  1:03 ` [PATCH 03/12] hwrng: bcm2835-rng: Move enabling to hwrng::init Florian Fainelli
2017-11-02  1:04 ` [PATCH 04/12] hwrng: bcm2835-rng: Implementation cleanup callback Florian Fainelli
2017-11-02  1:04 ` [PATCH 05/12] hwrng: bcm2835-rng: Use device managed helpers Florian Fainelli
2017-11-02  1:04 ` [PATCH 06/12] hwrng: bcm2835-rng: Rework interrupt masking Florian Fainelli
2017-11-02  1:04 ` [PATCH 07/12] hwrng: bcm2835-rng: Manage an optional clock Florian Fainelli
2017-11-04 13:50   ` Stefan Wahren
2017-11-04 17:59     ` Florian Fainelli
2017-11-04 18:22       ` Stefan Wahren
2017-11-04 19:37         ` Andrew Lunn [this message]
2017-11-04 20:08           ` Russell King - ARM Linux
2017-11-04 20:17             ` Andrew Lunn
2017-11-02  1:04 ` [PATCH 08/12] hwrng: bcm2835-rng: Abstract I/O accessors Florian Fainelli
2017-11-03 20:19   ` Eric Anholt
2017-11-03 22:04     ` Florian Fainelli
2017-11-02  1:04 ` [PATCH 09/12] hwrng: bcm2835-rng: Add Broadcom MIPS " Florian Fainelli
2017-11-02  1:04 ` [PATCH 10/12] dt-bindings: rng: Incorporate brcm,bcm6368.txt binding Florian Fainelli
2017-11-06 21:38   ` Rob Herring
2017-11-02  1:04 ` [PATCH 11/12] hwrng: bcm2835-rng: Enable BCM2835 RNG to work on BCM63xx platforms Florian Fainelli
2017-11-04 18:27   ` Stefan Wahren
2017-11-06 20:16     ` Florian Fainelli
2017-11-07  6:45       ` Stefan Wahren
2017-11-07 23:27         ` Stefan Wahren
2017-11-02  1:04 ` [PATCH 12/12] hwrng: bcm63xx-rng: Remove since bcm2835-rng takes over Florian Fainelli
2017-11-03 20:18   ` Eric Anholt
2017-11-03 21:58     ` Florian Fainelli
2017-11-02 19:00 ` [PATCH 00/12] bcm63xx-rng conversion to bcm2835-rng Stefan Wahren
2017-11-02 19:01 ` Stefan Wahren
2017-11-02 19:06   ` Florian Fainelli

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