Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753273AbcLMHWj convert rfc822-to-8bit (ORCPT ); Tue, 13 Dec 2016 02:22:39 -0500 Received: from nat-hk.nvidia.com ([203.18.50.4]:59727 "EHLO hkmmgate101.nvidia.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750801AbcLMHWh (ORCPT ); Tue, 13 Dec 2016 02:22:37 -0500 X-PGP-Universal: processed; by hkpgpgate102.nvidia.com on Mon, 12 Dec 2016 23:22:33 -0800 To: Matthew Wilcox CC: Andrew Morton , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" From: Alexandre Courbot Subject: Issue with DRM and "reimplement IDR and IDA using the radix tree" Organization: NVIDIA X-Nvconfidentiality: public Message-ID: Date: Tue, 13 Dec 2016 16:14:00 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 X-Originating-IP: [10.19.57.128] X-ClientProxiedBy: DRHKMAIL104.nvidia.com (10.25.59.18) To HKMAIL103.nvidia.com (10.18.16.12) Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 822 Lines: 21 Hi Matthew, Trying the latest -next on the Jetson TK1 board (with two different DRM devices and display and render), I noticed that the GPU device probe always failed with error -ENOSPC. After investigating I figured out that this was due to the minor device allocation failing when a second DRM device is added. More precisely, when drm_minor_alloc() is called with DRM_MINOR_PRIMARY (0) as argument for a second time, the call to idr_alloc() (which has a requested range of 0..64) fails instead of returning 1 as expected. Note that the first call is successful. Reverting "reimplement IDR and IDA using the radix tree" on 20161213's next fixes the issue for me, suggesting a bug may have slipped in there. Not sure how this could be fixed, so reporting the issue for now in case it is not known yet. Cheers, Alex.