From patchwork Tue May 23 21:04:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 685198 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72C57C7EE2F for ; Tue, 23 May 2023 21:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238663AbjEWVE7 (ORCPT ); Tue, 23 May 2023 17:04:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238533AbjEWVEo (ORCPT ); Tue, 23 May 2023 17:04:44 -0400 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53E9EDD; Tue, 23 May 2023 14:04:43 -0700 (PDT) Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-1ae6dce19f7so966465ad.3; Tue, 23 May 2023 14:04:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684875883; x=1687467883; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=gONh6AqSE8N1Psg514GpnJnE48CzNdfkrGouBQ/djr4=; b=nZUpMOBvl6yP+qAhDzHDqe1HYqYQC3avvla5rUfI76OKHwnGLf9zNQiyOpGTPqib09 9RMDyVtINPaXjHK6zJ/DmK7Fmjx22LLzSr+FbBz1mi5zfAovXMk6Y8mYWz2k5ODfmZKy ceYMm7Hwsi4O2vLsDxv7WXeRXsjorVtVUTnxrQBGMIg0NE3p2gzAivfzZXytjXVAlMeP V3oWa4gLTCap064aHhC2wDcZb9Jh9J401u2akwr4vqazL0PEmeKHKXDw3dDPtwUsjlZA y0msvzNJyQFyyuevsr+Ixm5r37nQ/4pE0mzLLUCDsZY2r1k6UjUFB9SV+MUOpQuQNQhs yvGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684875883; x=1687467883; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=gONh6AqSE8N1Psg514GpnJnE48CzNdfkrGouBQ/djr4=; b=O0Ycb71L6JNt5QtRYzsEdIHgNQlDVUqLJknmNeTexDewzCwEAECoeCvjuVf1M4BcTW 2Qx3Wk+6+XcJ939ZKPiYu52vjDVjOdJ5zOmTvZXDbvMP4of2uQUClG45tl8KTiXP+5e8 9bnWM5DI2HTdwp5o9uzY335Xe9kzwGp3xjAlbiiXfSn2gi42fF51gPZOELhLOBK0giCq Gh43IVnboPgh+2yt5afn5WtWEsgqAQNu4eiEMqw3qKNkrl0JInn2SX+Pn+EB3PSGRYJ/ nb3aM3F941kGcI9YbN9uFj0nuJYiEMoFyvIg0L2qWqz8M5W9Ze2Ei87HLXvUKsx6S79K sh4g== X-Gm-Message-State: AC+VfDya9UmnjD2a/EsMWBwGCxrNfg7cq95YqZZDy2UMqYIGheKI8OII aqAj1DNTNfVizvn8sW1MMls= X-Google-Smtp-Source: ACHHUZ4Dnt1VLPDpRGY9Y5FeKCb3CK0PNv4NJD8lKqy7SMpM7CB0fiB8o755iKbQgnJxYpWL811dkw== X-Received: by 2002:a17:903:18b:b0:1ad:d995:54a with SMTP id z11-20020a170903018b00b001add995054amr16689333plg.46.1684875882586; Tue, 23 May 2023 14:04:42 -0700 (PDT) Received: from dtor-ws.mtv.corp.google.com ([2620:15c:9d:2:3913:9c00:6a9e:2c95]) by smtp.gmail.com with ESMTPSA id y3-20020a17090322c300b001ab01b909c9sm7216892plg.120.2023.05.23.14.04.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 May 2023 14:04:41 -0700 (PDT) From: Dmitry Torokhov To: Jiri Kosina , Benjamin Tissoires Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Stephen Boyd Subject: [PATCH v2 2/2] HID: ensure timely release of driver-allocated resources Date: Tue, 23 May 2023 14:04:32 -0700 Message-ID: <20230523-hid-devres-v2-2-5220211a428c@gmail.com> X-Mailer: git-send-email 2.40.1.698.g37aff9b760-goog In-Reply-To: <20230523-hid-devres-v2-0-5220211a428c@gmail.com> References: <20230523-hid-devres-v2-0-5220211a428c@gmail.com> MIME-Version: 1.0 X-Mailer: b4 0.13-dev-2eb1a Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org More and more drivers rely on devres to manage their resources, however if bus' probe() and release() methods are not trivial and control some of resources as well (for example enable or disable clocks, or attach device to a power domain), we need to make sure that driver-allocated resources are released immediately after driver's remove() method returns, and not postponed until driver core gets around to releasing resources. In case of HID we should not try to close the report and release associated memory until after all devres callbacks are executed. To fix that we open a new devres group before calling driver's probe() and explicitly release it when we return from driver's remove(). This is similar to what we did for I2C bus in commit 5b5475826c52 ("i2c: ensure timely release of driver-allocated resources"). It is tempting to try and move this into driver core, but actually doing so is challenging, we need to split bus' remove() method into pre- and post-remove methods, which would make the logic even less clear. Reported-by: Stephen Boyd Link: https://lore.kernel.org/r/20230505232417.1377393-1-swboyd@chromium.org Signed-off-by: Dmitry Torokhov --- drivers/hid/hid-core.c | 17 +++++++++++++++++ include/linux/hid.h | 1 + 2 files changed, 18 insertions(+) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 1f0bb2784bfc..4b7062dcefec 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2614,6 +2614,10 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) if (!hid_check_device_match(hdev, hdrv, &id)) return -ENODEV; + hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL); + if (!hdev->devres_group_id) + return -ENOMEM; + /* reset the quirks that has been previously set */ hdev->quirks = hid_lookup_quirk(hdev); hdev->driver = hdrv; @@ -2626,7 +2630,16 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); } + /* + * Note that we are not closing the devres group opened above so + * even resources that were attached to the device after probe is + * run are released when hid_device_remove() is executed. This is + * needed as some drivers would allocate additional resources, + * for example when updating firmware. + */ + if (ret) { + devres_release_group(&hdev->dev, hdev->devres_group_id); hid_close_report(hdev); hdev->driver = NULL; } @@ -2669,6 +2682,10 @@ static void hid_device_remove(struct device *dev) hdrv->remove(hdev); else /* default remove */ hid_hw_stop(hdev); + + /* Release all devres resources allocated by the driver */ + devres_release_group(&hdev->dev, hdev->devres_group_id); + hid_close_report(hdev); hdev->driver = NULL; } diff --git a/include/linux/hid.h b/include/linux/hid.h index 4e4c4fe36911..39e21e3815ad 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -597,6 +597,7 @@ struct hid_device { /* device report descriptor */ struct semaphore driver_input_lock; /* protects the current driver */ struct device dev; /* device */ struct hid_driver *driver; + void *devres_group_id; /* ID of probe devres group */ const struct hid_ll_driver *ll_driver; struct mutex ll_open_lock;