From patchwork Thu Jun 13 02:10:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Rodrigo Siqueira X-Patchwork-Id: 10991029 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0574113AF for ; Thu, 13 Jun 2019 02:11:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E5D5E28957 for ; Thu, 13 Jun 2019 02:11:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D95102896F; Thu, 13 Jun 2019 02:11:07 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 898BD28985 for ; Thu, 13 Jun 2019 02:11:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1474589272; Thu, 13 Jun 2019 02:11:05 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-ed1-x542.google.com (mail-ed1-x542.google.com [IPv6:2a00:1450:4864:20::542]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4470389274; Thu, 13 Jun 2019 02:11:03 +0000 (UTC) Received: by mail-ed1-x542.google.com with SMTP id k21so25404960edq.3; Wed, 12 Jun 2019 19:11:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=0cVvTv62Az1HTrl8FUiIHyxSc2jG6hN8Hla75BR5w4M=; b=icivoTmYlkzsyniDAT9m2aiAKy9H/hbo2/j6AaMLWA06uRJcLg+ghmXBRVpi+WOJ5c O8T/C9EHDGplksE1bOqDpQbeiVa1JXaQ0BwybUDhMUC/G6R3YmYIkaqOQl17xf+LIOM+ f/LzaBLpaR+341J6ErkDuadYuCKzgREI3rfksn1yx10P1eQTV1VEP1w8GO6tbB0Ncy3I Z28cJsLjkJt5F2VLRIR8yUn3pJN73mcyrk//jfAzP40o7HGvGOxegXHSHBvhhIIR3C7O Ijw1GDuYC7QJwsgkd+6gMjbFuaagbwXc0Cw6WdFw3AFWY9wF23hMOG35GdBD6UHf6kBR 2/6A== X-Gm-Message-State: APjAAAXg1TZyhz1/HUPp+JDr/gKwIQ36p+CKnHKOgxDqhbUsAQNYHNEv DXQbTAVfxxb4vJXAAjl0P0c= X-Google-Smtp-Source: APXvYqzLd3ifguWITMiOZcgmncv5B0deo4wOLKQDnv7+CdbJeThnYCTF1jdNVtCFDE3yxhQCAIzN6g== X-Received: by 2002:a17:906:eb93:: with SMTP id mh19mr1902254ejb.42.1560391861842; Wed, 12 Jun 2019 19:11:01 -0700 (PDT) Received: from smtp.gmail.com ([187.121.151.146]) by smtp.gmail.com with ESMTPSA id d22sm267726ejm.83.2019.06.12.19.10.56 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 12 Jun 2019 19:11:00 -0700 (PDT) Date: Wed, 12 Jun 2019 23:10:54 -0300 From: Rodrigo Siqueira To: Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter Message-ID: <20190613021054.cdewdb3azy6zuoyw@smtp.gmail.com> MIME-Version: 1.0 User-Agent: NeoMutt/20180716 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=0cVvTv62Az1HTrl8FUiIHyxSc2jG6hN8Hla75BR5w4M=; b=QOaYprUy58aYx9mi4m91RPw+yTHHislGhUo783bCLgkBVWrShDTV6jY+zsCkdfCoqG eoauFxtYTWaOLjk5v68w7R1+0tVLBVRIGyEym6CgAfE5xjo+ZYn4i6532sT3AU3kseBw HoQYm9G+7u8HQjuPgvFyM5uitbZ3Ql+z37/l5YxAHXcJo1mkDgw54jy5iF6igvpJbclj b/OevCFYu83pizJrTwDy0DUaW89ilAnz4TvTdtnsSKkSOLrUowI7PvNQ+KC8FZkaXJhq KnU1FkSDXQXkmzOvDqXzkDwWFJ2gkAjRToM8IR/QdReoloeJTV+XiCeMMvUxeMVn++Tu aMUA== Subject: [Intel-gfx] [RESEND PATCH V3] drm/drm_vblank: Change EINVAL by the correct errno X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP For historical reason, the function drm_wait_vblank_ioctl always return -EINVAL if something gets wrong. This scenario limits the flexibility for the userspace make detailed verification of the problem and take some action. In particular, the validation of “if (!dev->irq_enabled)” in the drm_wait_vblank_ioctl is responsible for checking if the driver support vblank or not. If the driver does not support VBlank, the function drm_wait_vblank_ioctl returns EINVAL which does not represent the real issue; this patch changes this behavior by return EOPNOTSUPP. Additionally, some operations are unsupported by this function, and returns EINVAL; this patch also changes the return value to EOPNOTSUPP in this case. Lastly, the function drm_wait_vblank_ioctl is invoked by libdrm, which is used by many compositors; because of this, it is important to check if this change breaks any compositor. In this sense, the following projects were examined: * Drm-hwcomposer * Kwin * Sway * Wlroots * Wayland-core * Weston * Xorg (67 different drivers) For each repository the verification happened in three steps: * Update the main branch * Look for any occurrence "drmWaitVBlank" with the command: git grep -n "drmWaitVBlank" * Look in the git history of the project with the command: git log -SdrmWaitVBlank Finally, none of the above projects validate the use of EINVAL which make safe, at least for these projects, to change the return values. Change since V2: Daniel Vetter and Chris Wilson - Replace ENOTTY by EOPNOTSUPP - Return EINVAL if the parameters are wrong Signed-off-by: Rodrigo Siqueira Reviewed-by: Daniel Vetter --- Update: Now IGT has a way to validate if a driver has vblank support or not. See: https://gitlab.freedesktop.org/drm/igt-gpu-tools/commit/2d244aed69165753f3adbbd6468db073dc1acf9A drivers/gpu/drm/drm_vblank.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 0d704bddb1a6..d76a783a7d4b 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -1578,10 +1578,10 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, unsigned int flags, pipe, high_pipe; if (!dev->irq_enabled) - return -EINVAL; + return -EOPNOTSUPP; if (vblwait->request.type & _DRM_VBLANK_SIGNAL) - return -EINVAL; + return -EOPNOTSUPP; if (vblwait->request.type & ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |