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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/2] usb: phy: add a new driver for usb3 phy
Date: Thu, 27 Sep 2012 15:18:38 +0100	[thread overview]
Message-ID: <20120927141837.GA26268@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1348754648-8315-2-git-send-email-kishon@ti.com>

On Thu, Sep 27, 2012 at 07:34:07PM +0530, Kishon Vijay Abraham I wrote:
> +static int omap5_usb_phy_power(struct omap_usb *phy, bool on)
> +{
> +	u32 val;
> +	unsigned long rate;
> +	struct clk *sys_clk;
> +
> +	sys_clk = clk_get(NULL, "sys_clkin");
> +	if (IS_ERR(sys_clk)) {
> +		pr_err("%s: unable to get sys_clkin\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	rate = clk_get_rate(sys_clk);
> +	rate = rate/1000000;
> +	clk_put(sys_clk);

Actually, you're supposed to hold on to the struct clk all the time your
driver is making use of that - you're not supposed to drop it.

That has several advantages: if clk_get() fails, then you're failing
earlier on (when the driver is being probed) and when some event occurs.

  reply	other threads:[~2012-09-27 14:18 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-27 14:04 [PATCH v2 0/2] usb: phy: add usb3 phy driver Kishon Vijay Abraham I
2012-09-27 14:04 ` [PATCH v2 1/2] usb: phy: add a new driver for usb3 phy Kishon Vijay Abraham I
2012-09-27 14:18   ` Russell King - ARM Linux [this message]
2012-09-28  9:40     ` ABRAHAM, KISHON VIJAY
2012-09-27 14:04 ` [PATCH v2 2/2] usb: phy: omap-usb2: enable 960Mhz clock for omap5 Kishon Vijay Abraham I

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