From patchwork Tue May 23 21:04:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 685516 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 30AEDC7EE26 for ; Tue, 23 May 2023 21:04:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230512AbjEWVEn (ORCPT ); Tue, 23 May 2023 17:04:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238456AbjEWVEm (ORCPT ); Tue, 23 May 2023 17:04:42 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 987A1DD; Tue, 23 May 2023 14:04:41 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id d9443c01a7336-1a516fb6523so1154765ad.3; Tue, 23 May 2023 14:04:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684875881; x=1687467881; 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=7oif66uyid7/Yvwm1H8mOfwf8GcawmBSVr6I2ONcWn0=; b=eaj7DsiqHSBDRhIAp3W95sPbfFqH8kVwvK1Yc4IGVmaOOtaPu8jrI2Vrrjd4lR188W QYGQEyZbWloC6+cG2fuDhD3UcT9qWgKT9PEy8XU3Ni9lkOhPWrlV5F0qWqr0jRmnvsRR 90YYRinzUfBvMMURh9iDejeqwoSsAQO9T1GgE6D3iOSrfm9I/mj/c2rjaTZF7DS0yM9M zpGL8AAev5yqxCctIKnxDtYtFbz2YSStvRxVz7kCT60h2awAejTUK78O3ROYLdiJRUDy Tmm43FU3CmOTNIFetPZx7lDuQ/S7YNSGpggbQJepptpykxx0fhCJsU0lQoFcM3qTrvJL /3vQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684875881; x=1687467881; 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=7oif66uyid7/Yvwm1H8mOfwf8GcawmBSVr6I2ONcWn0=; b=FszbHCjko+NYNxCSY7m7QJIqD6BrnSpgm4K4J/L59W3SoHJBpP5b3g/wAd3HXnFOQt areTwPJWmlvICJL8XBsq/YNipDOtK0yV8XZorVQAsf9dyKfpiUKLJT8DT99ljLcGzW1Y 2OrpUoTtXrSOdt7axSi8UpEbfrCBnV0t/KeIt6hpeS8k1hPNKFE7SygBnJwiniQqTlHG NPgYBFnq+HAtCgGkQB5exnqmZinK3OFZAAZbVf3w0SmI7t67XTqYmj7WMMVqjGt1QrEx JviuAUrKuOytTAXq/FI+FcTbr7+ZTa+WW8uEZbGNPet1y9pFQiyVPcEK/6Uzg+qEdCDi yMiw== X-Gm-Message-State: AC+VfDxM3p2sdnHeqzJYP6rVMznhdmjcwlgtr4ybLDWtpw1rjzfsUzDi bFXPHoI+yTzzLxOBtvM28gY= X-Google-Smtp-Source: ACHHUZ4WLFV50r9QIriAzhdsMMgUdgzOIfsPg76cqeSZmHXzJiqkJr/WO26gwZzoeodUjaMbVth40w== X-Received: by 2002:a17:902:6b8c:b0:1af:bae0:6bed with SMTP id p12-20020a1709026b8c00b001afbae06bedmr4847449plk.56.1684875880956; Tue, 23 May 2023 14:04:40 -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.120.2023.05.23.14.04.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 May 2023 14:04:40 -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 1/2] HID: split apart hid_device_probe to make logic more apparent Date: Tue, 23 May 2023 14:04:31 -0700 Message-ID: <20230523-hid-devres-v2-1-5220211a428c@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 hid_device_probe() has a complex flow and locks and unlocks a mutex. Move the most of the logic into __hid_device_probe() and hid_check_device_match() and leave the locking in hid_device_probe() which makes the code more clear. Signed-off-by: Dmitry Torokhov --- drivers/hid/hid-core.c | 101 ++++++++++++++++++++++++++----------------------- 1 file changed, 54 insertions(+), 47 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 22623eb4f72f..1f0bb2784bfc 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2587,64 +2587,71 @@ bool hid_compare_device_paths(struct hid_device *hdev_a, } EXPORT_SYMBOL_GPL(hid_compare_device_paths); +static bool hid_check_device_match(struct hid_device *hdev, + struct hid_driver *hdrv, + const struct hid_device_id **id) +{ + *id = hid_match_device(hdev, hdrv); + if (!*id) + return -ENODEV; + + if (hdrv->match) + return hdrv->match(hdev, hid_ignore_special_drivers); + + /* + * hid-generic implements .match(), so we must be dealing with a + * different HID driver here, and can simply check if + * hid_ignore_special_drivers is set or not. + */ + return !hid_ignore_special_drivers; +} + +static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) +{ + const struct hid_device_id *id; + int ret; + + if (!hid_check_device_match(hdev, hdrv, &id)) + return -ENODEV; + + /* reset the quirks that has been previously set */ + hdev->quirks = hid_lookup_quirk(hdev); + hdev->driver = hdrv; + + if (hdrv->probe) { + ret = hdrv->probe(hdev, id); + } else { /* default probe */ + ret = hid_open_report(hdev); + if (!ret) + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); + } + + if (ret) { + hid_close_report(hdev); + hdev->driver = NULL; + } + + return ret; +} + static int hid_device_probe(struct device *dev) { - struct hid_driver *hdrv = to_hid_driver(dev->driver); struct hid_device *hdev = to_hid_device(dev); - const struct hid_device_id *id; + struct hid_driver *hdrv = to_hid_driver(dev->driver); int ret = 0; - if (down_interruptible(&hdev->driver_input_lock)) { - ret = -EINTR; - goto end; - } - hdev->io_started = false; + if (down_interruptible(&hdev->driver_input_lock)) + return -EINTR; + hdev->io_started = false; clear_bit(ffs(HID_STAT_REPROBED), &hdev->status); - if (!hdev->driver) { - id = hid_match_device(hdev, hdrv); - if (id == NULL) { - ret = -ENODEV; - goto unlock; - } + if (!hdev->driver) + ret = __hid_device_probe(hdev, hdrv); - if (hdrv->match) { - if (!hdrv->match(hdev, hid_ignore_special_drivers)) { - ret = -ENODEV; - goto unlock; - } - } else { - /* - * hid-generic implements .match(), so if - * hid_ignore_special_drivers is set, we can safely - * return. - */ - if (hid_ignore_special_drivers) { - ret = -ENODEV; - goto unlock; - } - } - - /* reset the quirks that has been previously set */ - hdev->quirks = hid_lookup_quirk(hdev); - hdev->driver = hdrv; - if (hdrv->probe) { - ret = hdrv->probe(hdev, id); - } else { /* default probe */ - ret = hid_open_report(hdev); - if (!ret) - ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); - } - if (ret) { - hid_close_report(hdev); - hdev->driver = NULL; - } - } -unlock: if (!hdev->io_started) up(&hdev->driver_input_lock); -end: + return ret; }