From patchwork Wed May 31 00:05:46 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michel Thierry X-Patchwork-Id: 9755627 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 9710A60390 for ; Wed, 31 May 2017 00:05:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B0782847A for ; Wed, 31 May 2017 00:05:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7FB622848B; Wed, 31 May 2017 00:05:49 +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=-4.2 required=2.0 tests=BAYES_00, 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 2AA3228474 for ; Wed, 31 May 2017 00:05:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E8ADF6E122; Wed, 31 May 2017 00:05:47 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id EE1556E122 for ; Wed, 31 May 2017 00:05:46 +0000 (UTC) Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP; 30 May 2017 17:05:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.38,420,1491289200"; d="scan'208";a="93041784" Received: from relo-linux-11.sc.intel.com ([10.3.160.214]) by orsmga004.jf.intel.com with ESMTP; 30 May 2017 17:05:46 -0700 From: Michel Thierry To: intel-gfx@lists.freedesktop.org Date: Tue, 30 May 2017 17:05:46 -0700 Message-Id: <20170531000546.30762-1-michel.thierry@intel.com> X-Mailer: git-send-email 2.11.0 Subject: [Intel-gfx] [PATCH] drm/i915/guc: Fix doorbell id selection X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We are passing parameters in the wrong order to find next zero bit, and when it doesn't find anything it returns size (offset in the code), which is always zero. For reference the function is defined as: find_next_bit( *addr, size, offset ) The incorrect parameter order was added by commit abddffdf3620e ("drm/i915/guc: Sanitize GuC client initialization"). Luckily, currently we only use a single guc client and a single doorbell, which happens to be zero; therefore it isn't necessary to backport this fix (which would be for v4.12). Cc: Daniele Ceraolo Spurio Cc: Joonas Lahtinen Cc: Oscar Mateo Signed-off-by: Michel Thierry Reviewed-by: Daniele Ceraolo Spurio --- drivers/gpu/drm/i915/i915_guc_submission.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index fb936bb5cb93..ec391ef981aa 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -105,7 +105,7 @@ static int __reserve_doorbell(struct i915_guc_client *client) end += offset; } - id = find_next_zero_bit(client->guc->doorbell_bitmap, offset, end); + id = find_next_zero_bit(client->guc->doorbell_bitmap, end, offset); if (id == end) return -ENOSPC;