Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759110AbbLCIv5 (ORCPT ); Thu, 3 Dec 2015 03:51:57 -0500 Received: from dgate20.ts.fujitsu.com ([80.70.172.51]:50529 "EHLO dgate20.ts.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbbLCIvz (ORCPT ); Thu, 3 Dec 2015 03:51:55 -0500 DomainKey-Signature: s=s1536a; d=ts.fujitsu.com; c=nofws; q=dns; h=X-SBRSScore:Received:Received:Received:From:To:Cc: Subject:Date:Message-Id:X-Mailer:In-Reply-To:References; b=qyo0JX/6NdcHnh6N/jZ/4clperdCuA4SWUpjLsvkGZqBCKIbzVEmBQ/H ia0KYnHFzUmQvvb7LZHB7BiUIBKEjuBYGUBJolbbWAlkpoJmyeQiI70NY ms3ld8PjW5tBqE2rv28BP0z9E9HcbpmgZtP2RgtwB+AgBlZ3NyWt6C6zz PJFiQMcricXU69I23kkMEKbH6GKLL0QPyw08fM2uox5hBhThAmRkNv/vI OKphJXlVLgKHFYM+POML7Jhpa9XCs; X-SBRSScore: None From: martin.wilck@ts.fujitsu.com To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, u.kleine-koenig@pengutronix.de Cc: tpmdd-devel@lists.sourceforge.net, Martin Wilck Subject: [PATCH v3] base/platform: fix binding for drivers without probe callback Date: Thu, 3 Dec 2015 09:51:44 +0100 Message-Id: <1449132704-9952-1-git-send-email-martin.wilck@ts.fujitsu.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <20151202165338.GA18274@kroah.com> References: <20151202165338.GA18274@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2411 Lines: 63 From: Martin Wilck Since b8b2c7d845d5, platform_drv_probe() is called for all platform devices. If drv->probe is NULL, and dev_pm_domain_attach() fails, platform_drv_probe() will return the error code from dev_pm_domain_attach(). This causes real_probe() to enter the "probe_failed" path and set dev->driver to NULL. Before b8b2c7d845d5, real_probe() would assume success if both dev->bus->probe and drv->probe were missing. As a result, a device and driver could be "bound" together just by matching their names; this doesn't work any more after b8b2c7d845d5. This change broke the assumptions of certain drivers; for example, the TPM code has long assumed that platform driver and device with matching name could be bound in this way. That assumption may cause such drivers to fail with Oops during initialization after applying this change. Failure in suspend/resume tests under qemu has also been reported. This patch restores the previous (4.3.0 and earlier) behavior of platform_drv_probe() in the case when the associated platform driver has no "probe" function. Fixes: b8b2c7d845d5 ("base/platform: assert that dev_pm_domain callbacks are called unconditionally") Signed-off-by: Martin Wilck --- v2: fixed style issues, rephrased commit message. v3: rephrased commit message and subject again. drivers/base/platform.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 1dd6d3b..176b59f 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -513,10 +513,15 @@ static int platform_drv_probe(struct device *_dev) return ret; ret = dev_pm_domain_attach(_dev, true); - if (ret != -EPROBE_DEFER && drv->probe) { - ret = drv->probe(dev); - if (ret) - dev_pm_domain_detach(_dev, true); + if (ret != -EPROBE_DEFER) { + if (drv->probe) { + ret = drv->probe(dev); + if (ret) + dev_pm_domain_detach(_dev, true); + } else { + /* don't fail if just dev_pm_domain_attach failed */ + ret = 0; + } } if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) { -- 1.8.3.1 -- 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/