From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [RFC PATCH for Juno 1/2] net: smsc911x add support for probing from ACPI Date: Mon, 1 Sep 2014 18:27:11 +0100 Message-ID: <20140901172711.GI608@arm.com> References: <1409583961-7466-1-git-send-email-hanjun.guo@linaro.org> <1409583961-7466-2-git-send-email-hanjun.guo@linaro.org> <20140901170447.GF608@arm.com> <21764799.KDNDm9XRax@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from fw-tnat.austin.arm.com ([217.140.110.23]:23196 "EHLO collaborate-mta1.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751954AbaIAR1V (ORCPT ); Mon, 1 Sep 2014 13:27:21 -0400 Content-Disposition: inline In-Reply-To: <21764799.KDNDm9XRax@wuerfel> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Arnd Bergmann Cc: "linux-arm-kernel@lists.infradead.org" , "hanjun.guo@linaro.org" , Mark Rutland , "linaro-acpi@lists.linaro.org" , Will Deacon , Lv Zheng , Rob Herring , Lorenzo Pieralisi , Daniel Lezcano , Robert Moore , "linux-acpi@vger.kernel.org" , "grant.likely@linaro.org" , Charles Garcia-Tobin , Robert Richter , Jason Cooper , Marc Zyngier , Liviu Dudau , Mark Brown , Bjorn Helgaas , "graeme.gregory@linaro.org" On Mon, Sep 01, 2014 at 06:11:44PM +0100, Arnd Bergmann wrote: > On Monday 01 September 2014 18:04:47 Catalin Marinas wrote: > > On Mon, Sep 01, 2014 at 04:06:00PM +0100, Hanjun Guo wrote: > > > +#ifdef CONFIG_ACPI > > > +/* Configure some sensible defaults for ACPI mode */ > > > +static int smsc911x_probe_config_acpi(struct smsc911x_platform_config *config, > > > + acpi_handle *ahandle) > > > +{ > > > + if (!ahandle) > > > + return -ENOSYS; > > > + > > > + config->phy_interface = PHY_INTERFACE_MODE_MII; > > > + > > > + config->flags |= SMSC911X_USE_32BIT; > > > + > > > + config->irq_polarity = SMSC911X_IRQ_POLARITY_ACTIVE_HIGH; > > > + > > > + config->irq_type = SMSC911X_IRQ_TYPE_PUSH_PULL; > > > + > > > + return 0; > > > +} > > > +#else > > > > I don't like this and it shows issues we have with ACPI on certain ARM > > platforms. You hard-code these values to match the Juno platform. What > > if we get another SoC which has different configuration here? For DT, we > > have the smsc911x_probe_config_dt() which reads the relevant information > > from DT. I think this kind of configuration would be more suitable as > > _DSD properties and sharing the similar names with DT (but we go back to > > the question about who's in charge of the _DSD properties). > > Good point, I totally missed that. > > There is of course the possibility to set those values based on the > acpi_device_id, but that is exactly the part that _DSD is trying to > avoid. I would prefer to avoid acpi_device_id checks. This would defeat the alleged aim of ACPI to run newer hardware configuration with older kernels. > > > static int smsc911x_drv_probe(struct platform_device *pdev) > > > { > > > struct device_node *np = pdev->dev.of_node; > > > + acpi_handle *ahandle = ACPI_HANDLE(&pdev->dev); > > > struct net_device *dev; > > > struct smsc911x_data *pdata; > > > struct smsc911x_platform_config *config = dev_get_platdata(&pdev->dev); > > > @@ -2436,6 +2464,9 @@ static int smsc911x_drv_probe(struct platform_device *pdev) > > > } > > > > > > retval = smsc911x_probe_config_dt(&pdata->config, np); > > > + if (retval) > > > + retval = smsc911x_probe_config_acpi(&pdata->config, ahandle); > > > + > > > > In most of the ACPI patches so far we check for ACPI first with DT as a > > fall-back if ACPI is not enabled. This changes here. > > Does this really make a difference? Not the order (well, someone may think that if they unflatten the DT in a vendor kernel even though it boot as ACPI, they could get away with a mix of DT and ACPI ;)). > > I would prefer > > something which probes only ACPI if the ACPI is enabled (run-time, not > > config) otherwise DT only. E.g. > > (example missing?) I was looking through the code and forgot. Something like: if (acpi_disabled) retval = smsc911x_probe_config_dt(); else retval = smsc911x_probe_config_acpi(); > I think we should have the equivalent of of_have_populated_dt(), to > check whether acpi is being used to boot, and have that new function > be hardcoded to zero in case of !IS_ENABLED(CONFIG_ACPI). I think you meant hardcoded to 1 when !ACPI. That would work as well. -- Catalin