From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH v2 1/2] usb: phy: add a new driver for usb3 phy Date: Thu, 27 Sep 2012 15:18:38 +0100 Message-ID: <20120927141837.GA26268@n2100.arm.linux.org.uk> References: <1348754648-8315-1-git-send-email-kishon@ti.com> <1348754648-8315-2-git-send-email-kishon@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1348754648-8315-2-git-send-email-kishon-l0cyMroinI0@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kishon Vijay Abraham I Cc: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org, rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org, rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Felipe Balbi , Moiz Sonasath List-Id: linux-omap@vger.kernel.org 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. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html