Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754262AbbKLKtt (ORCPT ); Thu, 12 Nov 2015 05:49:49 -0500 Received: from regular1.263xmail.com ([211.150.99.132]:58515 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751048AbbKLKts (ORCPT ); Thu, 12 Nov 2015 05:49:48 -0500 X-263anti-spam: KSV:0;BIG:0;ABS:1;DNS:0;ATT:0;SPF:S; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 1 X-SKE-CHECKED: 1 X-ADDR-CHECKED: 0 X-RL-SENDER: mark.yao@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: mark.yao@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Message-ID: <56446EC2.6020301@rock-chips.com> Date: Thu, 12 Nov 2015 18:49:38 +0800 From: Mark yao User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Liviu Dudau CC: Daniel Vetter , David Airlie , Rob Clark , DRI devel , lkml Subject: Re: drm: Bogus WARN() in drm_atomic_helper_update_legacy_modeset_state() ? References: <20151110150102.GP963@e106497-lin.cambridge.arm.com> <56444EA1.3050506@rock-chips.com> <20151112103618.GY963@e106497-lin.cambridge.arm.com> In-Reply-To: <20151112103618.GY963@e106497-lin.cambridge.arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6494 Lines: 148 On 2015年11月12日 18:36, Liviu Dudau wrote: > On Thu, Nov 12, 2015 at 04:32:33PM +0800, Mark yao wrote: >> On 2015年11月10日 23:01, Liviu Dudau wrote: >> >> Hello, >> >> When booting my Juno board with the HDLCD driver that I have converted to >> atomic operations I'm getting the following warning: >> >> ------------[ cut here ]------------ >> WARNING: at /work/repositories/kernel/drivers/gpu/drm/drm_atomic_helper.c:674 >> Modules linked in: hdlcd(+) clk_scpi >> >> CPU: 3 PID: 1375 Comm: systemd-udevd Not tainted 4.3.0-next-20151109+ #5 >> Hardware name: ARM Juno development board (r0) (DT) >> task: ffffffc974888b00 ti: ffffffc9755dc000 task.ti: ffffffc9755dc000 >> PC is at drm_atomic_helper_update_legacy_modeset_state+0x204/0x20c >> LR is at drm_atomic_helper_commit_modeset_disables+0x1c0/0x394 >> pc : [] lr : [] pstate: 20000145 >> sp : ffffffc9755df430 >> x29: ffffffc9755df430 x28: ffffffc975703600 >> x27: 0000000000000000 x26: ffffffc976253960 >> x25: ffffffc976254040 x24: ffffffc000819000 >> x23: ffffffc000689ea0 x22: ffffffc976251800 >> x21: ffffffc976251800 x20: 0000000000000000 >> x19: ffffffc9766b1f80 x18: 00000000715fe015 >> x17: 0000007fb4b855b0 x16: 0000000000000220 >> x15: 0000000000000001 x14: 0ffffffffffffffe >> x13: 0000000000000008 x12: 0101010101010101 >> x11: ffffffc000964000 x10: ffffffc0009d2000 >> x9 : 0000000000000000 x8 : ffffffc97ff5f700 >> x7 : ffffffc97566cb80 x6 : ffffffc9766b1700 >> x5 : ffffffc975665100 x4 : 0000000000000000 >> x3 : ffffffc976253960 x2 : ffffffc97566cd00 >> x1 : ffffffc976253900 x0 : 0000000000000000 >> >> ---[ end trace 9fe289f798e7178e ]--- >> Call trace: >> [] drm_atomic_helper_update_legacy_modeset_state+0x204/0x20c >> [] drm_atomic_helper_commit_modeset_disables+0x1c0/0x394 >> [] drm_atomic_helper_commit+0xe0/0x150 >> [] drm_atomic_commit+0x40/0x6c >> [] restore_fbdev_mode+0x294/0x2d4 >> [] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x8c >> [] drm_fb_helper_set_par+0x2c/0x58 >> [] fbcon_init+0x4d4/0x534 >> [] visual_init+0xac/0x104 >> [] do_bind_con_driver+0x16c/0x398 >> [] do_take_over_console+0xd8/0x1f4 >> [] do_fbcon_takeover+0x74/0xf8 >> [] fbcon_event_notify+0x8a4/0x8f8 >> [] notifier_call_chain+0x4c/0x88 >> [] __blocking_notifier_call_chain+0x44/0x74 >> [] blocking_notifier_call_chain+0x14/0x1c >> [] fb_notifier_call_chain+0x1c/0x24 >> [] register_framebuffer+0x1c0/0x2ac >> [] drm_fb_helper_initial_config+0x25c/0x3ec >> [] drm_fbdev_cma_init+0x98/0x134 >> [] hdlcd_drm_bind+0x180/0x498 [hdlcd] >> [] try_to_bring_up_master.part.5+0xd4/0x118 >> [] component_master_add_with_match+0xc4/0x148 >> [] component_master_add+0x10/0x18 >> [] hdlcd_probe+0x14/0x28 [hdlcd] >> [] platform_drv_probe+0x54/0xc0 >> [] driver_probe_device+0x1ec/0x2e8 >> [] __driver_attach+0x9c/0xa0 >> [] bus_for_each_dev+0x58/0x98 >> [] driver_attach+0x20/0x28 >> [] bus_add_driver+0x1c8/0x22c >> [] driver_register+0x68/0x108 >> [] __platform_driver_register+0x4c/0x54 >> [] hdlcd_init+0x18/0x30 [hdlcd] >> [] do_one_initcall+0x90/0x1a8 >> [] do_init_module+0x60/0x1c8 >> [] load_module+0x1554/0x1c98 >> [] SyS_finit_module+0x7c/0x88 >> [] el0_svc_naked+0x24/0x28 >> >> >> The line that triggers the warning is: >> >> 674: WARN_ON(!connector->encoder->crtc); >> >> As far as I can see the encoder->crtc value is being set to a non-NULL value only >> in two places: >> - in drm_atomic_helper_update_legacy_modeset_state() after WARN_ON() >> encoder->crtc = connector->state->crtc; >> - in drm_crtc_helper_set_config(drm_mode_set *set): >> encoder->crtc = new_crtc; >> >> Nothing in the call path from drm_atomic_commit() calls crtc_funcs->set_config() or >> drm_crtc_helper_set_config() directly, so the question is if this WARN() is actually >> valid. >> >> Call path from drm_atomic_commit: >> >> drm_atomic_helper_commit() >> - drm_atomic_helper_prepare_planes() >> - drm_atomic_helper_swap_state() >> - drm_atomic_helper_commit_modeset_disables() >> - disable_outputs() >> - drm_atomic_helper_update_legacy_modeset_state() >> - WARN_ON(!connector->encoder->crtc) >> >> Best regards, >> Liviu >> >> >> Hi Liviu >> I solved this problem by following change, you can check if your driver do the same things: >> drivers/gpu/drm/bridge/dw_hdmi.c: >> - hdmi->connector.encoder = encoder; >> +// hdmi->connector.encoder = encoder; >> >> drm_mode_connector_attach_encoder(&hdmi->connector, encoder); >> >> I found some other drivers set connector.encoder before drm_mode_connector_attach_encoder, some are not. >> >> drm_mode_connector_attach_encoder already describe the link of connector and encoder, >> so I think "connector.encoder = encoder" is not needed, is that right? > I'll have a look, thanks for pointing this. However, my setup uses the tda998x driver for encoder, so I will > have to go look there rather than in my driver. > > Best regards, > Liviu > >> Thanks. >> >> -- >> Ｍark Yao Hi Liviu drivers/gpu/drm/i2c/tda998x_drv.c do the same things: priv->connector.encoder = &priv->encoder; drm_mode_connector_attach_encoder(&priv->connector, &priv->encoder); I believe must be same problem. Thanks. -- Ｍark Yao -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/