From patchwork Wed Nov 1 19:28:21 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Limonciello, Mario" X-Patchwork-Id: 10036999 X-Patchwork-Delegate: dvhart@infradead.org 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 73CAE6032D for ; Wed, 1 Nov 2017 19:28:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 79694205A4 for ; Wed, 1 Nov 2017 19:28:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6E29827CEA; Wed, 1 Nov 2017 19:28:48 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable 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 F1164205A4 for ; Wed, 1 Nov 2017 19:28:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755113AbdKAT2d (ORCPT ); Wed, 1 Nov 2017 15:28:33 -0400 Received: from esa4.dell-outbound.iphmx.com ([68.232.149.214]:1359 "EHLO esa4.dell-outbound.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755106AbdKAT2b (ORCPT ); Wed, 1 Nov 2017 15:28:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=dell.com; i=@dell.com; q=dns/txt; s=smtpout; t=1509564511; x=1541100511; h=from:to:cc:subject:date:message-id; bh=TEUzoN/rAxdMNLaZt3ZdUYZdEbpIxvORQ4MHE4TohPU=; b=XlLoKv4P2/umf0INQfRP3OYwVhkq5yYQuEMLToHsrdr5FPGBC5dj8mlF Uz4nGFjCWlU3AA6dl4KQER/Unm/vVg6zndaz8HSChBlJPb9Sq9lS5zRWP pJ7C+pYS37d4qG6mjgPKfhtcHyDBrgzzSd5oUxY3bykVWIfA/DJg2nitV Y=; Received: from esa4.dell-outbound2.iphmx.com ([68.232.154.98]) by esa4.dell-outbound.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Nov 2017 14:28:31 -0500 Received: from ausxipps306.us.dell.com ([143.166.148.156]) by esa4.dell-outbound2.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Nov 2017 01:28:31 +0600 X-LoopCount0: from 10.208.86.39 X-IronPort-AV: E=Sophos;i="5.44,330,1505797200"; d="scan'208";a="168270769" X-DLP: DLP_GlobalPCIDSS From: Mario Limonciello To: dvhart@infradead.org, Andy Shevchenko Cc: LKML , platform-driver-x86@vger.kernel.org, pali.rohar@gmail.com, Mario Limonciello Subject: [PATCH] platform/x86: dell-*wmi*: Relay failed initial probe to dependent drivers Date: Wed, 1 Nov 2017 14:28:21 -0500 Message-Id: X-Mailer: git-send-email 2.7.4 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP dell-wmi and dell-smbios-wmi are dependent upon dell-wmi-descriptor finishing probe successfully to probe themselves. Currently if dell-wmi-descriptor fails probing in a non-recoverable way (such as invalid header) dell-wmi and dell-smbios-wmi will continue to try to redo probing due to deferred probing. To solve this have the dependent drivers query the dell-wmi-descriptor driver whether the descriptor has been determined valid. The possible results are: -EPROBE_DEFER: Descriptor not yet probed, dependent driver should wait and use deferred probing < 0: Descriptor probed, invalid. Dependent driver should return an error. 0: Successful descriptor probe, dependent driver can continue Successful descriptor probe still doesn't mean that the descriptor driver is necessarily bound at the time of initialization of dependent driver. Userspace can unbind the driver, so all methods used from driver should still be verified to return success values otherwise deferred probing be used. Signed-off-by: Mario Limonciello --- Note: this patch is intendended on top of the 16 patch series that introduces WMI support. At the time of this submission, v12 is the latest submission of that series. drivers/platform/x86/dell-smbios-wmi.c | 4 ++++ drivers/platform/x86/dell-wmi-descriptor.c | 33 ++++++++++++++++++++++-------- drivers/platform/x86/dell-wmi-descriptor.h | 7 +++++++ drivers/platform/x86/dell-wmi.c | 5 +++++ 4 files changed, 41 insertions(+), 8 deletions(-) diff --git a/drivers/platform/x86/dell-smbios-wmi.c b/drivers/platform/x86/dell-smbios-wmi.c index 35c13815b24c..3fa53fa174b2 100644 --- a/drivers/platform/x86/dell-smbios-wmi.c +++ b/drivers/platform/x86/dell-smbios-wmi.c @@ -151,6 +151,10 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev) if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID)) return -ENODEV; + ret = dell_wmi_get_descriptor_valid(); + if (ret) + return ret; + priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv), GFP_KERNEL); if (!priv) diff --git a/drivers/platform/x86/dell-wmi-descriptor.c b/drivers/platform/x86/dell-wmi-descriptor.c index 3204c408e261..33c6c7d66f8c 100644 --- a/drivers/platform/x86/dell-wmi-descriptor.c +++ b/drivers/platform/x86/dell-wmi-descriptor.c @@ -26,9 +26,16 @@ struct descriptor_priv { u32 interface_version; u32 size; }; +static int descriptor_valid; static LIST_HEAD(wmi_list); static DEFINE_MUTEX(list_mutex); +int dell_wmi_get_descriptor_valid(void) +{ + return descriptor_valid; +} +EXPORT_SYMBOL_GPL(dell_wmi_get_descriptor_valid); + bool dell_wmi_get_interface_version(u32 *version) { struct descriptor_priv *priv; @@ -79,18 +86,17 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev) union acpi_object *obj = NULL; struct descriptor_priv *priv; u32 *buffer; - int ret; obj = wmidev_block_query(wdev, 0); if (!obj) { dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); - ret = -EIO; + descriptor_valid = -EIO; goto out; } if (obj->type != ACPI_TYPE_BUFFER) { dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); - ret = -EINVAL; + descriptor_valid = -EINVAL; goto out; } @@ -101,7 +107,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev) dev_err(&wdev->dev, "Dell descriptor buffer has unexpected length (%d)\n", obj->buffer.length); - ret = -EINVAL; + descriptor_valid = -EINVAL; goto out; } @@ -110,7 +116,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev) if (strncmp(obj->string.pointer, "DELL WMI", 8) != 0) { dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n", buffer); - ret = -EINVAL; + descriptor_valid = -EINVAL; goto out; } @@ -123,7 +129,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev) priv->interface_version = buffer[2]; priv->size = buffer[3]; - ret = 0; + descriptor_valid = 0; dev_set_drvdata(&wdev->dev, priv); mutex_lock(&list_mutex); list_add_tail(&priv->list, &wmi_list); @@ -135,7 +141,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev) out: kfree(obj); - return ret; + return descriptor_valid; } static int dell_wmi_descriptor_remove(struct wmi_device *wdev) @@ -162,7 +168,18 @@ static struct wmi_driver dell_wmi_descriptor_driver = { .id_table = dell_wmi_descriptor_id_table, }; -module_wmi_driver(dell_wmi_descriptor_driver); +static int __init dell_wmi_descriptor_init(void) +{ + descriptor_valid = -EPROBE_DEFER; + return wmi_driver_register(&dell_wmi_descriptor_driver); +} +module_init(dell_wmi_descriptor_init); + +static void __exit dell_wmi_descriptor_exit(void) +{ + wmi_driver_unregister(&dell_wmi_descriptor_driver); +} +module_exit(dell_wmi_descriptor_exit); MODULE_ALIAS("wmi:" DELL_WMI_DESCRIPTOR_GUID); MODULE_AUTHOR("Mario Limonciello "); diff --git a/drivers/platform/x86/dell-wmi-descriptor.h b/drivers/platform/x86/dell-wmi-descriptor.h index 5f7b69c2c83a..776cddd5e135 100644 --- a/drivers/platform/x86/dell-wmi-descriptor.h +++ b/drivers/platform/x86/dell-wmi-descriptor.h @@ -15,6 +15,13 @@ #define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" +/* possible return values: + * -EPROBE_DEFER: probing for dell-wmi-descriptor not yet run + * 0: valid descriptor, successfully probed + * < 0: invalid descriptor, don't probe dependent devices + */ +int dell_wmi_get_descriptor_valid(void); + bool dell_wmi_get_interface_version(u32 *version); bool dell_wmi_get_size(u32 *size); diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index 54321080a30d..bb7c1e681792 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -655,10 +655,15 @@ static int dell_wmi_events_set_enabled(bool enable) static int dell_wmi_probe(struct wmi_device *wdev) { struct dell_wmi_priv *priv; + int ret; if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID)) return -ENODEV; + ret = dell_wmi_get_descriptor_valid(); + if (ret) + return ret; + priv = devm_kzalloc( &wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL); if (!priv)