From patchwork Tue May 24 18:13:15 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Steinar H. Gunderson" X-Patchwork-Id: 9134181 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3F0ED6075E for ; Tue, 24 May 2016 19:25:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2DD4E28220 for ; Tue, 24 May 2016 19:25:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 22B092825C; Tue, 24 May 2016 19:25:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9909228220 for ; Tue, 24 May 2016 19:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932195AbcEXTZH (ORCPT ); Tue, 24 May 2016 15:25:07 -0400 Received: from cassarossa.samfundet.no ([193.35.52.29]:38328 "EHLO cassarossa.samfundet.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932201AbcEXTZH (ORCPT ); Tue, 24 May 2016 15:25:07 -0400 Received: from pannekake.samfundet.no ([2001:67c:29f4::50] ident=unknown) by cassarossa.samfundet.no with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1b5Hwo-0007HG-20; Tue, 24 May 2016 21:24:58 +0200 Received: from sesse by pannekake.samfundet.no with local (Exim 4.84_2) (envelope-from ) id 1b5Hwn-0005Be-UA; Tue, 24 May 2016 21:24:57 +0200 In-Reply-To: <20160524192424.GA11690@sesse.net> References: <20160524192424.GA11690@sesse.net> From: "Steinar H. Gunderson" Date: Tue, 24 May 2016 20:13:15 +0200 Subject: [PATCH] dwc3-exynos: Fix deferred probing storm. To: k.kozlowski@samsung.com Cc: broonie@debian.org, linux-samsung-soc@vger.kernel.org, 823552@bugs.debian.org, balbi@kernel.org, linux-usb@vger.kernel.org Message-Id: Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP dwc3-exynos has two problems during init if the regulators are slow to come up (for instance if the I2C bus driver is not on the initramfs) and return probe deferral. First, every time this happens, the driver leaks the USB phys created; they need to be deallocated on error. Second, since the phy devices are created before the regulators fail, this means that there's a new device to re-trigger deferred probing, which causes it to essentially go into a busy loop of re-probing the device until the regulators come up. Move the phy creation to after the regulators have succeeded, and also fix cleanup on failure. On my ODROID XU4 system (with Debian's initramfs which doesn't contain the I2C driver), this reduces the number of probe attempts (for each of the two controllers) from more than 2000 to eight. Reported-by: Steinar H. Gunderson Signed-off-by: Steinar H. Gunderson Reviewed-by: Krzysztof Kozlowski Reviewed-by: Vivek Gautam --- drivers/usb/dwc3/dwc3-exynos.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c index dd5cb55..2f1fb7e 100644 --- a/drivers/usb/dwc3/dwc3-exynos.c +++ b/drivers/usb/dwc3/dwc3-exynos.c @@ -128,12 +128,6 @@ static int dwc3_exynos_probe(struct platform_device *pdev) platform_set_drvdata(pdev, exynos); - ret = dwc3_exynos_register_phys(exynos); - if (ret) { - dev_err(dev, "couldn't register PHYs\n"); - return ret; - } - exynos->dev = dev; exynos->clk = devm_clk_get(dev, "usbdrd30"); @@ -183,20 +177,29 @@ static int dwc3_exynos_probe(struct platform_device *pdev) goto err3; } + ret = dwc3_exynos_register_phys(exynos); + if (ret) { + dev_err(dev, "couldn't register PHYs\n"); + goto err4; + } + if (node) { ret = of_platform_populate(node, NULL, NULL, dev); if (ret) { dev_err(dev, "failed to add dwc3 core\n"); - goto err4; + goto err5; } } else { dev_err(dev, "no device node, failed to add dwc3 core\n"); ret = -ENODEV; - goto err4; + goto err5; } return 0; +err5: + platform_device_unregister(exynos->usb2_phy); + platform_device_unregister(exynos->usb3_phy); err4: regulator_disable(exynos->vdd10); err3: