Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932569Ab3CLONZ (ORCPT ); Tue, 12 Mar 2013 10:13:25 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:47132 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932392Ab3CLONW (ORCPT ); Tue, 12 Mar 2013 10:13:22 -0400 Message-ID: <513F37DD.9030301@ti.com> Date: Tue, 12 Mar 2013 16:12:45 +0200 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Marc Kleine-Budde CC: , , , , , , Subject: Re: [PATCH 1/8] usb: phy: nop: Add some parameters to platform data References: <1363087466-32444-1-git-send-email-rogerq@ti.com> <1363087466-32444-2-git-send-email-rogerq@ti.com> <513F177D.40500@pengutronix.de> In-Reply-To: <513F177D.40500@pengutronix.de> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1537 Lines: 34 On 03/12/2013 01:54 PM, Marc Kleine-Budde wrote: > On 03/12/2013 12:24 PM, Roger Quadros wrote: >> Add clk_rate parameter to platform data. If supplied, the >> NOP phy driver will program the clock to that rate during probe. >> >> Also add 2 flags, needs_vcc and needs_reset. >> If the flag is set and the regulator couldn't be found >> then the driver will bail out with -EPROBE_DEFER. > > Is there a platform which fills out pdata.needs_vcc and > pdata.needs_reset? IMHO it makes no sense to add features for the non DT > case, if there isn't any user for it. > There can be a user in the non DT case as well. Consider the following example: The power regulator that supplies VCC to the PHY device sits over the I2C bus. The NOP transceiver driver is built into the kernel but the regulator driver is built as a module. During boot, the NOP transceiver driver's probe is called before the regulator can be probed. So regulator_get() will fail and if the platform doesn't set the needs_vcc flag, the driver will continue as normal and the PHY device won't work. I know that beagleboard can benefit from this. The current workaround is to register the regulator before we register the PHY in the board file. With the needs_vcc flag, we don't need to have that limitation. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/