From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kishon Vijay Abraham I Subject: Re: [PATCH v3 04/10] usb: dwc3: use quirks to know if a particualr platform doesn't have PHY Date: Wed, 11 Dec 2013 14:37:16 +0530 Message-ID: <52A82B44.10408@ti.com> References: <1385373690-12170-1-git-send-email-kishon@ti.com> <1385373690-12170-5-git-send-email-kishon@ti.com> <20131204144027.GB21055@xps8300> <52A01E86.50406@ti.com> <20131205075828.GA32583@xps8300> <52A56DA1.1010808@ti.com> <20131209092604.GC5231@xps8300> <20131211085320.GD28456@xps8300> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131211085320.GD28456@xps8300> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Heikki Krogerus , balbi@ti.com Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, ijc+devicetree@hellion.org.uk, linux@arm.linux.org.uk, rob@landley.net, pawel.moll@arm.com, linux-doc@vger.kernel.org, tony@atomide.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, rob.herring@calxeda.com, grant.likely@linaro.org, bcousson@baylibre.com, galak@codeaurora.org, swarren@wwwdotorg.org, s.nawrocki@samsung.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Wednesday 11 December 2013 02:23 PM, Heikki Krogerus wrote: > Hi, > > On Mon, Dec 09, 2013 at 11:26:04AM +0200, Heikki Krogerus wrote: >>>>>> Can you guys explain why is something like this needed? Like with >>>>>> clocks and gpios, the device drivers shouldn't need to care any more >>>>>> if the platform has the phys or not. -ENODEV tells you your platform >>>>> >>>>> Shouldn't we report if a particular platform needs a PHY and not able to get >>>>> it. How will a user know if a particular controller is not working because it's >>>>> not able to get and initialize the PHYs? Don't you think in such cases it's >>>>> better to fail (and return from probe) because the controller will not work >>>>> anyway without the PHY? >>>> >>>> My point is that you do not need to separately tell this to the driver >>>> like you do with the quirks (if you did, then you would need to fix >>>> your framework and not hack the drivers). >>>> >>>> Like I said, ENODEV tells you that there is no phy on this platform >>>> for you, allowing you to safely continue. If your phy driver is not >>>> loaded, the framework already returns EPROBE_DEFER, right. Any other >>> >>> right. but that doesn't consider broken dt data. With quirks we'll >>> able to tell if a controller in a particular platform has PHY or not >>> without depending on the dt data. >> >> Broken dt data? What kind of scenario are you thinking here? Do you >> mean case where the dt does not describe the phy on a platform that >> depends on it? Shouldn't that problem be fixed in the dt and not >> hacked in the drivers? Or are you thinking about something else? >> >> Is there a case where something like that is actually happening? > > I'm guessing I'm not getting an answer to this one. > > Look, this patch will not work with ACPI enumerated devices. We will > have a platform providing a single ACPI id, but there is a whole bunch > of boards based on it and we have no way of telling which of them > need/have phys to deal with and which ones don't. Alright.. I'll drop this patch then. Thanks Kishon