Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753159Ab3IQNEb (ORCPT ); Tue, 17 Sep 2013 09:04:31 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:51090 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687Ab3IQNE2 convert rfc822-to-8bit (ORCPT ); Tue, 17 Sep 2013 09:04:28 -0400 From: "Strashko, Grygorii" To: Thierry Reding , Greg Kroah-Hartman , Linus Walleij , Stephen Warren , Wolfram Sang , Grant Likely , Rob Herring , Benjamin Herrenschmidt , Thomas Gleixner CC: "linux-kernel@vger.kernel.org" , "linux-gpio@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "devicetree@vger.kernel.org" Subject: RE: [PATCH 7/9] of/platform: Resolve interrupt references at probe time Thread-Topic: [PATCH 7/9] of/platform: Resolve interrupt references at probe time Thread-Index: AQHOsreZgkoiZ41uWkOwoWWSHnYI+JnJ4ywG Date: Tue, 17 Sep 2013 13:04:06 +0000 Message-ID: <902E09E6452B0E43903E4F2D568737AB363BD3@DNCE04.ent.ti.com> References: <1379320326-13241-1-git-send-email-treding@nvidia.com>,<1379320326-13241-8-git-send-email-treding@nvidia.com> In-Reply-To: <1379320326-13241-8-git-send-email-treding@nvidia.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [137.167.131.94] x-exclaimer-md-config: f9c360f5-3d1e-4c3c-8703-f45bf52eff6b Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5794 Lines: 166 Hi Thierry, On 09/16/2013 11:32 AM, Thierry Reding wrote:> Interrupt references are currently resolved very early (when a device is > created). This has the disadvantage that it will fail in cases where the > interrupt parent hasn't been probed and no IRQ domain for it has been > registered yet. To work around that various drivers use explicit > initcall ordering to force interrupt parents to be probed before devices > that need them are created. That's error prone and doesn't always work. > If a platform device uses an interrupt line connected to a different > platform device (such as a GPIO controller), both will be created in the > same batch, and the GPIO controller won't have been probed by its driver > when the depending platform device is created. Interrupt resolution will > fail in that case. > > Another common workaround is for drivers to explicitly resolve interrupt > references at probe time. This is suboptimal, however, because it will > require every driver to duplicate the code. > > This patch adds support for late interrupt resolution to the platform > driver core, by resolving the references right before a device driver's > .probe() function will be called. This not only delays the resolution > until a much later time (giving interrupt parents a better chance of > being probed in the meantime), but it also allows the platform driver > core to queue the device for deferred probing if the interrupt parent > hasn't registered its IRQ domain yet. > > Signed-off-by: Thierry Reding > --- > drivers/base/platform.c | 4 ++++ > drivers/of/platform.c | 43 +++++++++++++++++++++++++++++++++++++------ > include/linux/of_platform.h | 7 +++++++ > 3 files changed, 48 insertions(+), 6 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 4f8bef3..8dcf835 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -481,6 +481,10 @@ static int platform_drv_probe(struct device *_dev) Should it be the part of really_probe()? Isn't it? > struct platform_device *dev = to_platform_device(_dev); > int ret; > > + ret = of_platform_probe(dev); > + if (ret) > + return ret; > + > if (ACPI_HANDLE(_dev)) > acpi_dev_pm_attach(_dev, true); > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index 9b439ac..edaef70 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -142,7 +142,7 @@ struct platform_device *of_device_alloc(struct device_node *np, > struct device *parent) > { > struct platform_device *dev; > - int rc, i, num_reg = 0, num_irq; > + int rc, i, num_reg = 0; > struct resource *res, temp_res; > > dev = platform_device_alloc("", -1); > @@ -153,23 +153,21 @@ struct platform_device *of_device_alloc(struct device_node *np, > if (of_can_translate_address(np)) > while (of_address_to_resource(np, num_reg, &temp_res) == 0) > num_reg++; > - num_irq = of_irq_count(np); > > /* Populate the resource table */ > - if (num_irq || num_reg) { > - res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL); > + if (num_reg) { > + res = kzalloc(sizeof(*res) * num_reg, GFP_KERNEL); > if (!res) { > platform_device_put(dev); > return NULL; > } > > - dev->num_resources = num_reg + num_irq; > + dev->num_resources = num_reg; > dev->resource = res; > for (i = 0; i < num_reg; i++, res++) { > rc = of_address_to_resource(np, i, res); > WARN_ON(rc); > } > - WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq); > } > > dev->dev.of_node = of_node_get(np); > @@ -490,4 +488,37 @@ int of_platform_populate(struct device_node *root, > return rc; > } > EXPORT_SYMBOL_GPL(of_platform_populate); > + > +int of_platform_probe(struct platform_device *pdev) > +{ > + struct device_node *np = pdev->dev.of_node; > + int num_irq, ret = 0; > + > + if (!pdev->dev.of_node) > + return 0; > + > + num_irq = of_irq_count(pdev->dev.of_node); > + if (num_irq > 0) { > + struct resource *res = pdev->resource; > + int num_reg = pdev->num_resources; > + int num = num_reg + num_irq; > + > + res = krealloc(res, num * sizeof(*res), GFP_KERNEL); > + if (!res) > + return -ENOMEM; > + > + pdev->num_resources = num; > + pdev->resource = res; > + res += num_reg; What will happen if Driver probe is failed or deferred? Seems resource table size will grow each time the Driver probe is deferred or failed. > + > + ret = of_irq_to_resource_table(np, res, num_irq); > + if (ret < 0) > + return ret; > + > + WARN_ON(ret != num_irq); > + ret = 0; > + } > + > + return ret; > +} > #endif /* CONFIG_OF_ADDRESS */ > diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h > index 05cb4a9..92fc4f6 100644 > --- a/include/linux/of_platform.h > +++ b/include/linux/of_platform.h > @@ -72,6 +72,8 @@ extern int of_platform_populate(struct device_node *root, > const struct of_device_id *matches, > const struct of_dev_auxdata *lookup, > struct device *parent); > + > +extern int of_platform_probe(struct platform_device *pdev); > #else > static inline int of_platform_populate(struct device_node *root, > const struct of_device_id *matches, > @@ -80,6 +82,11 @@ static inline int of_platform_populate(struct device_node *root, > { > return -ENODEV; > } > + > +static inline int of_platform_probe(struct platform_device *pdev) > +{ > + return 0; > +} > #endif > > #endif /* _LINUX_OF_PLATFORM_H */ > Regards, - grygorii -- 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/