Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760954Ab3GSSPE (ORCPT ); Fri, 19 Jul 2013 14:15:04 -0400 Received: from www.linutronix.de ([62.245.132.108]:51109 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752622Ab3GSSPA (ORCPT ); Fri, 19 Jul 2013 14:15:00 -0400 From: Sebastian Andrzej Siewior To: Rob Herring , Grant Likely Cc: linux-omap@vger.kernel.org, linux-samsung-soc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Sebastian Andrzej Siewior , Tony Lindgren , Doug Anderson , Vivek Gautam , Naveen Krishna Chatradhi , Kukjin Kim , Kishon Vijay Abraham I , Roger Quadros , George Cherian , Felipe Balbi Subject: [PATCH] of: provide of_platform_unpopulate() Date: Fri, 19 Jul 2013 20:14:51 +0200 Message-Id: <1374257691-31981-1-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 1.8.3.2 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8830 Lines: 267 So I called of_platform_populate() on a device to get each child device probed and on rmmod and I need to reverse its doing. After a quick grep I did what others did as well and rmmod ended in: | Unable to handle kernel NULL pointer dereference at virtual address 00000018 | PC is at release_resource+0x18/0x80 | Process rmmod (pid: 2005, stack limit = 0xedc30238) | [] (release_resource+0x18/0x80) from [] (platform_device_del+0x78/0xac) | [] (platform_device_del+0x78/0xac) from [] (platform_device_unregister+0xc/0x18) The problem is that platform_device_del() "releases" each ressource in its tree. This does not work on platform_devices created by OF becuase they were never added via insert_resource(). As a consequence old->parent in __release_resource() is NULL and we explode while accessing ->child. So I either I do something completly wrong _or_ nobody here tested the rmmod path of their driver. This patch provides a common function to unregister / remove devices which added to the system via of_platform_populate(). While this works now on my test case I have not tested any of the driver I modify here so feedback is greatly appreciated. Cc: Tony Lindgren Cc: Doug Anderson Cc: Vivek Gautam Cc: Naveen Krishna Chatradhi Cc: Kukjin Kim Cc: Kishon Vijay Abraham I Cc: Roger Quadros Cc: George Cherian Cc: Felipe Balbi Signed-off-by: Sebastian Andrzej Siewior --- drivers/bus/omap-ocp2scp.c | 13 ++----------- drivers/iio/adc/exynos_adc.c | 15 ++------------- drivers/mfd/omap-usb-host.c | 9 +-------- drivers/of/platform.c | 22 ++++++++++++++++++++++ drivers/usb/dwc3/dwc3-exynos.c | 11 +---------- drivers/usb/dwc3/dwc3-omap.c | 12 +----------- include/linux/of_platform.h | 4 ++++ 7 files changed, 33 insertions(+), 53 deletions(-) diff --git a/drivers/bus/omap-ocp2scp.c b/drivers/bus/omap-ocp2scp.c index 5511f98..510bb9e 100644 --- a/drivers/bus/omap-ocp2scp.c +++ b/drivers/bus/omap-ocp2scp.c @@ -23,15 +23,6 @@ #include #include -static int ocp2scp_remove_devices(struct device *dev, void *c) -{ - struct platform_device *pdev = to_platform_device(dev); - - platform_device_unregister(pdev); - - return 0; -} - static int omap_ocp2scp_probe(struct platform_device *pdev) { int ret; @@ -51,7 +42,7 @@ static int omap_ocp2scp_probe(struct platform_device *pdev) return 0; err0: - device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices); + of_platform_unpopulate(&pdev->dev); return ret; } @@ -59,7 +50,7 @@ static int omap_ocp2scp_probe(struct platform_device *pdev) static int omap_ocp2scp_remove(struct platform_device *pdev) { pm_runtime_disable(&pdev->dev); - device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices); + of_platform_unpopulate(&pdev->dev); return 0; } diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 9809fc9..10248e1 100644 --- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -216,15 +216,6 @@ static const struct iio_chan_spec exynos_adc_iio_channels[] = { ADC_CHANNEL(9, "adc9"), }; -static int exynos_adc_remove_devices(struct device *dev, void *c) -{ - struct platform_device *pdev = to_platform_device(dev); - - platform_device_unregister(pdev); - - return 0; -} - static void exynos_adc_hw_init(struct exynos_adc *info) { u32 con1, con2; @@ -357,8 +348,7 @@ static int exynos_adc_probe(struct platform_device *pdev) return 0; err_of_populate: - device_for_each_child(&pdev->dev, NULL, - exynos_adc_remove_devices); + of_platform_unpopulate(&pdev->dev); regulator_disable(info->vdd); clk_disable_unprepare(info->clk); err_iio_dev: @@ -375,8 +365,7 @@ static int exynos_adc_remove(struct platform_device *pdev) struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct exynos_adc *info = iio_priv(indio_dev); - device_for_each_child(&pdev->dev, NULL, - exynos_adc_remove_devices); + of_platform_unpopulate(&pdev->dev); regulator_disable(info->vdd); clk_disable_unprepare(info->clk); writel(0, info->enable_reg); diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c index 759fae3..bb26cea 100644 --- a/drivers/mfd/omap-usb-host.c +++ b/drivers/mfd/omap-usb-host.c @@ -832,13 +832,6 @@ static int usbhs_omap_probe(struct platform_device *pdev) return ret; } -static int usbhs_omap_remove_child(struct device *dev, void *data) -{ - dev_info(dev, "unregistering\n"); - platform_device_unregister(to_platform_device(dev)); - return 0; -} - /** * usbhs_omap_remove - shutdown processing for UHH & TLL HCDs * @pdev: USB Host Controller being removed @@ -871,7 +864,7 @@ static int usbhs_omap_remove(struct platform_device *pdev) pm_runtime_disable(&pdev->dev); /* remove children */ - device_for_each_child(&pdev->dev, NULL, usbhs_omap_remove_child); + of_platform_unpopulate(&pdev->dev); return 0; } diff --git a/drivers/of/platform.c b/drivers/of/platform.c index e0a6514..9cbb0c3 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -473,4 +473,26 @@ int of_platform_populate(struct device_node *root, return rc; } EXPORT_SYMBOL_GPL(of_platform_populate); + +static int of_remove_populated_child(struct device *dev, void *d) +{ + struct platform_device *pdev = to_platform_device(dev); + + of_device_unregister(pdev); + return 0; +} +/** + * of_platform_unpopulate() - Remove populated devices. + * @parent: parent of the populated devices. + * + * The reverse of of_platform_populate() and can only be used a parent was + * specified while invoking the former. + */ +void of_platform_unpopulate(struct device *parent) +{ + if (WARN_ON(!parent)) + return; + device_for_each_child(parent, NULL, of_remove_populated_child); +} +EXPORT_SYMBOL_GPL(of_platform_unpopulate); #endif /* CONFIG_OF_ADDRESS */ diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c index 8ce9d7f..2bf5664 100644 --- a/drivers/usb/dwc3/dwc3-exynos.c +++ b/drivers/usb/dwc3/dwc3-exynos.c @@ -86,15 +86,6 @@ static int dwc3_exynos_register_phys(struct dwc3_exynos *exynos) return ret; } -static int dwc3_exynos_remove_child(struct device *dev, void *unused) -{ - struct platform_device *pdev = to_platform_device(dev); - - platform_device_unregister(pdev); - - return 0; -} - static int dwc3_exynos_probe(struct platform_device *pdev) { struct dwc3_exynos *exynos; @@ -164,7 +155,7 @@ static int dwc3_exynos_remove(struct platform_device *pdev) { struct dwc3_exynos *exynos = platform_get_drvdata(pdev); - device_for_each_child(&pdev->dev, NULL, dwc3_exynos_remove_child); + of_platform_unpopulate(&pdev->dev); platform_device_unregister(exynos->usb2_phy); platform_device_unregister(exynos->usb3_phy); diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c index 077f110..8688613 100644 --- a/drivers/usb/dwc3/dwc3-omap.c +++ b/drivers/usb/dwc3/dwc3-omap.c @@ -327,15 +327,6 @@ static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap) return IRQ_HANDLED; } -static int dwc3_omap_remove_core(struct device *dev, void *c) -{ - struct platform_device *pdev = to_platform_device(dev); - - platform_device_unregister(pdev); - - return 0; -} - static void dwc3_omap_enable_irqs(struct dwc3_omap *omap) { u32 reg; @@ -529,8 +520,7 @@ static int dwc3_omap_remove(struct platform_device *pdev) dwc3_omap_disable_irqs(omap); pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); - device_for_each_child(&pdev->dev, NULL, dwc3_omap_remove_core); - + of_platform_unpopulate(&pdev->dev); return 0; } diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h index 05cb4a9..e354f9c 100644 --- a/include/linux/of_platform.h +++ b/include/linux/of_platform.h @@ -72,6 +72,7 @@ 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 void of_platform_unpopulate(struct device *parent); #else static inline int of_platform_populate(struct device_node *root, const struct of_device_id *matches, @@ -80,6 +81,9 @@ static inline int of_platform_populate(struct device_node *root, { return -ENODEV; } +static inline void of_platform_unpopulate(struct device *parent) +{ +} #endif #endif /* _LINUX_OF_PLATFORM_H */ -- 1.8.3.2 -- 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/