From patchwork Wed Jun 8 01:28:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Yakir Yang X-Patchwork-Id: 9163213 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 5A9AC60571 for ; Wed, 8 Jun 2016 01:30:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AE2728365 for ; Wed, 8 Jun 2016 01:30:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F70528373; Wed, 8 Jun 2016 01:30:36 +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=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2A57628365 for ; Wed, 8 Jun 2016 01:30:35 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bASIw-0002CR-Ma; Wed, 08 Jun 2016 01:29:10 +0000 Received: from lucky1.263xmail.com ([211.157.147.135]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bASIs-0001pD-J9; Wed, 08 Jun 2016 01:29:08 +0000 Received: from ykk?rock-chips.com (unknown [192.168.167.105]) by lucky1.263xmail.com (Postfix) with SMTP id 1D9CE724; Wed, 8 Jun 2016 09:28:39 +0800 (CST) X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 Received: from [192.168.2.101] (localhost.localdomain [127.0.0.1]) by smtp.263.net (Postfix) with ESMTP id C0B692415C; Wed, 8 Jun 2016 09:28:31 +0800 (CST) X-RL-SENDER: ykk@rock-chips.com X-FST-TO: marc.zyngier@arm.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: ykk@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-SENDER: ykk@rock-chips.com X-DNS-TYPE: 0 Received: from [192.168.2.101] (unknown [58.22.7.114]) by smtp.263.net (Postfix) whith ESMTP id 28238HX7C7G; Wed, 08 Jun 2016 09:28:36 +0800 (CST) Subject: Re: [PATCH v14.1 01/17] drm: bridge: analogix/dp: split exynos dp driver to bridge directory To: Javier Martinez Canillas References: <1455534485-1154-1-git-send-email-ykk@rock-chips.com> <1455534576-1486-1-git-send-email-ykk@rock-chips.com> <1811552.qvsCm7GUs1@diego> <417ed48e-74e1-f747-34b9-0d1031a3d862@osg.samsung.com> From: Yakir Yang Message-ID: <575774C0.4000900@rock-chips.com> Date: Wed, 8 Jun 2016 09:28:32 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <417ed48e-74e1-f747-34b9-0d1031a3d862@osg.samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160607_182907_150210_DF424856 X-CRM114-Status: GOOD ( 27.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Krzysztof Kozlowski , =?UTF-8?Q?Heiko_St=c3=bcbner?= , Seung-Woo Kim , djkurtz@chromium.org, Andrzej Hajda , Gustavo Padovan , linux-samsung-soc@vger.kernel.org, Russell King , Joonyoung Shim , Kishon Vijay Abraham I , linux-rockchip@lists.infradead.org, Kukjin Kim , robherring2@gmail.com, Thierry Reding , devicetree@vger.kernel.org, Pawel Moll , Ian Campbell , Marc Zyngier , Inki Dae , Rob Herring , Sean Paul , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, Mark Yao , Jingoo Han , emil.l.velikov@gmail.com, linux-kernel@vger.kernel.org, Kyungmin Park , Kumar Gala , ajaynumb@gmail.com, Andy Yan Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Javier, On 06/08/2016 01:06 AM, Javier Martinez Canillas wrote: > Hello Yakir, > > On 03/17/2016 05:47 PM, Heiko Stübner wrote: >> Split the dp core driver from exynos directory to bridge directory, >> and rename the core driver to analogix_dp_*, rename the platform >> code to exynos_dp. >> >> Beside the new analogix_dp driver would export six hooks. >> "analogix_dp_bind()" and "analogix_dp_unbind()" >> "analogix_dp_suspned()" and "analogix_dp_resume()" >> "analogix_dp_detect()" and "analogix_dp_get_modes()" >> >> The bind/unbind symbols is used for analogix platform driver to connect >> with analogix_dp core driver. And the detect/get_modes is used for analogix >> platform driver to init the connector. >> >> They reason why connector need register in helper driver is rockchip drm >> haven't implement the atomic API, but Exynos drm have implement it, so >> there would need two different connector helper functions, that's why we >> leave the connector register in helper driver. >> >> Signed-off-by: Yakir Yang >> --- > Marc reported that his Exynos5250 Snow Chromebook fails to boot with v4.7-rc. > > I've done a git bisect and tracked down to this commit. The problem is a NULL > pointer dereference to connector->dev in drm_mode_create(connector->dev) when > called from exynos_dp_get_modes(). The error log is at [1]. > > I'm trying to figure out the issue but wanted to mention in case you have any > hints about what could be the cause. AFAICT the problem is related to the fact > that drm_connector_init() is called in analogix_dp_bridge_attach() and the > connector passed as argument is the one in struct analogix_dp_device *dp, but > later exynos_dp_get_modes() calls drm_mode_create() passing the connector in > struct exynos_dp_device *dp, which has not been previously initialized. Agree, this should be the problem, exynos_dp->connector haven't been initialized, driver should make exynos_dp->dp to a connector point, and record the passing connector in exynos_dp_bridge_attach(), that should fix this problem. Thanks, - Yakir @@ -103,6 +103,7 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data, int ret; drm_connector_register(connector); + dp->connector = connector; /* Pre-empt DP connector creation if there's a bridge */ if (dp->ptn_bridge) { > [1] > [ 4.175676] Unable to handle kernel NULL pointer dereference at virtual address 00000210 > [ 4.182793] pgd = c0004000 > [ 4.185171] [00000210] *pgd=00000000 > [ 4.188657] Internal error: Oops: 5 [#1] PREEMPT SMP ARM > [ 4.194164] Modules linked in: > [ 4.196964] CPU: 1 PID: 68 Comm: kworker/1:1 Not tainted 4.7.0-rc2-next-20160606-00006-g876c3150327a #97 > [ 4.206565] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [ 4.212582] Workqueue: events hdmi_hotplug_work_func > [ 4.217383] task: ed758000 ti: ed75c000 task.ti: ed75c000 > [ 4.222887] PC is at __mutex_lock_slowpath+0x6c/0x404 > [ 4.227913] LR is at preempt_count_add+0xa4/0x140 > [ 4.232592] pc : [] lr : [] psr: 60000093 > [ 4.232592] sp : ed75dd80 ip : 00000000 fp : ee8c1180 > [ 4.244193] r10: 00000300 r9 : ed758000 r8 : 00000001 > [ 4.249262] r7 : 60000013 r6 : c0b473a8 r5 : 00000210 r4 : 0000020c > [ 4.261955] r3 : 00000000 r2 : 00000001 r1 : ee8c2808 r0 : 00000000 > [ 4.273270] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none > [ 4.285336] Control: 10c5387d Table: 4000406a DAC: 00000051 > [ 4.295885] Process kworker/1:1 (pid: 68, stack limit = 0xed75c210) > [ 4.306979] Stack: (0xed75dd80 to 0xed75e000) > [ 4.316102] dd80: ee8c1180 c03dd21c ee8f0820 00000001 0000020c 0000020c 00000000 00000000 > [ 4.329201] dda0: 00000001 dededede 00000300 c06d2578 ee8c2808 c03d00f4 ee801d80 c0b0261c > [ 4.342362] ddc0: 00000041 ee8c2800 00000000 00000001 ee8f0810 ee8f0b65 c074d2b4 c03d35b0 > [ 4.353140] dde0: 00000000 00000300 ee8c1180 c03d81d0 c387cf74 ee8f0820 00000001 c03eaffc > [ 4.361811] de00: 00000000 ee8f0820 00000001 c03f28bc ee8f0b65 c06d400c ee8c1180 006d40a4 > [ 4.370483] de20: 00000000 01820a11 81010300 00000100 00000064 ee8f085c ee8f0820 c0b1f894 > [ 4.379150] de40: c3872800 c0b82fac c074d2b4 c03b7550 c0b13274 c0327974 00000001 eefb8530 > [ 4.387805] de60: 00000556 00000000 c38729b0 c3872800 ee8c1180 00000001 ee8c7000 00000000 > [ 4.396467] de80: 00000556 00000300 c38729b0 00000002 ee8c1180 c03c107c ee8c7000 c3872800 > [ 4.405121] dea0: ee8c7240 c3872800 c0b82fac c03c3268 c3872ad4 00000001 c3872ae0 c03b7af0 > [ 4.413776] dec0: eefb8000 c0139804 00000000 c0136484 ee8a0000 ee8c1180 c3870b4c eefb7b00 > [ 4.422415] dee0: eefbb000 00000000 00000000 eefb7b00 ee8c1180 c012ff2c 00000008 eefb7b24 > [ 4.431045] df00: eefb7b00 ee8c1198 00000008 eefb7b24 c0b02100 ed75c000 eefb7b00 c0130178 > [ 4.439664] df20: ed75c000 ee863040 ee8c1180 00000000 ee863040 ee8c1180 c0130140 00000000 > [ 4.448274] df40: 00000000 00000000 00000000 c0135454 00000000 00000000 00000000 ee8c1180 > [ 4.456879] df60: 00000000 00000000 dead4ead ffffffff ffffffff ed75df74 ed75df74 00000000 > [ 4.465462] df80: 00000000 dead4ead ffffffff ffffffff ed75df90 ed75df90 ed75dfac ee863040 > [ 4.474028] dfa0: c0135378 00000000 00000000 c0107978 00000000 00000000 00000000 00000000 > [ 4.482597] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > [ 4.491133] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 > [ 4.499643] [] (__mutex_lock_slowpath) from [] (mutex_lock+0xc/0x24) > [ 4.507102] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready > [ 4.514264] [] (mutex_lock) from [] (drm_mode_object_get_reg+0x28/0x80) > [ 4.522981] [] (drm_mode_object_get_reg) from [] (drm_mode_object_get+0x18/0x20) > [ 4.532491] [] (drm_mode_object_get) from [] (drm_mode_create+0x3c/0x58) > [ 4.541316] [] (drm_mode_create) from [] (exynos_dp_get_modes+0x24/0x80) > [ 4.550160] [] (exynos_dp_get_modes) from [] (analogix_dp_get_modes+0x198/0x278) > [ 4.559735] [] (analogix_dp_get_modes) from [] (drm_helper_probe_single_connector_modes+0x114/0x554) > [ 4.571078] [] (drm_helper_probe_single_connector_modes) from [] (drm_fb_helper_probe_connector_modes+0x48/0x68) > [ 4.583513] [] (drm_fb_helper_probe_connector_modes) from [] (drm_fb_helper_hotplug_event+0x70/0xdc) > [ 4.594921] [] (drm_fb_helper_hotplug_event) from [] (drm_helper_hpd_irq_event+0xd4/0x160) > [ 4.605474] [] (drm_helper_hpd_irq_event) from [] (process_one_work+0x124/0x338) > [ 4.615144] [] (process_one_work) from [] (worker_thread+0x38/0x4d4) > [ 4.623764] [] (worker_thread) from [] (kthread+0xdc/0xf4) > [ 4.631512] [] (kthread) from [] (ret_from_fork+0x14/0x3c) > [ 4.639239] Code: e10f7000 f10c0080 e2845004 f595f000 (e1953f9f) > [ 4.645845] ---[ end trace 3bfc770b9638a54b ]--- > > Best regards, Tested-by: Marc Zyngier diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c index 468498e..4c1fb3f 100644 --- a/drivers/gpu/drm/exynos/exynos_dp.c +++ b/drivers/gpu/drm/exynos/exynos_dp.c @@ -34,7 +34,7 @@ struct exynos_dp_device { struct drm_encoder encoder; - struct drm_connector connector; + struct drm_connector *connector; struct drm_bridge *ptn_bridge; struct drm_device *drm_dev; struct device *dev; @@ -70,7 +70,7 @@ static int exynos_dp_poweroff(struct analogix_dp_plat_data *plat_data) static int exynos_dp_get_modes(struct analogix_dp_plat_data *plat_data) { struct exynos_dp_device *dp = to_dp(plat_data); - struct drm_connector *connector = &dp->connector; + struct drm_connector *connector = dp->connector; struct drm_display_mode *mode; int num_modes = 0;