From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F20DAC43603 for ; Wed, 18 Dec 2019 18:08:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD0202072B for ; Wed, 18 Dec 2019 18:08:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727767AbfLRSI0 (ORCPT ); Wed, 18 Dec 2019 13:08:26 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2207 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727650AbfLRSIV (ORCPT ); Wed, 18 Dec 2019 13:08:21 -0500 Received: from lhreml705-cah.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 1D71896BD28CD8A35F4B; Wed, 18 Dec 2019 18:08:19 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml705-cah.china.huawei.com (10.201.108.46) with Microsoft SMTP Server (TLS) id 14.3.408.0; Wed, 18 Dec 2019 18:08:18 +0000 Received: from [127.0.0.1] (10.202.226.46) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 18 Dec 2019 18:08:18 +0000 Subject: Re: Warnings in DRM code when removing/unbinding a driver From: John Garry To: Ezequiel Garcia , "kongxinwei (A)" , "Chenfeng (puck)" , "airlied@linux.ie" , "daniel@ffwll.ch" , CC: Linuxarm , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , , References: <07899bd5-e9a5-cff0-395f-b4fb3f0f7f6c@huawei.com> Message-ID: Date: Wed, 18 Dec 2019 18:08:17 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.202.226.46] X-ClientProxiedBy: lhreml712-chm.china.huawei.com (10.201.108.63) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + So the v5.4 kernel does not have this issue. I have bisected the initial occurrence to: commit 37a48adfba6cf6e87df9ba8b75ab85d514ed86d8 Author: Thomas Zimmermann Date: Fri Sep 6 14:20:53 2019 +0200 drm/vram: Add kmap ref-counting to GEM VRAM objects The kmap and kunmap operations of GEM VRAM buffers can now be called in interleaving pairs. The first call to drm_gem_vram_kmap() maps the buffer's memory to kernel address space and the final call to drm_gem_vram_kunmap() unmaps the memory. Intermediate calls to these functions increment or decrement a reference counter. So this either exposes or creates the issue. John >> On Mon, 2019-12-16 at 17:23 +0000, John Garry wrote: >>> Hi all, >>> >>> Enabling CONFIG_DEBUG_TEST_DRIVER_REMOVE causes many warns on a system >>> with the HIBMC hw: >>> >>> [   27.788806] WARNING: CPU: 24 PID: 1 at >>> drivers/gpu/drm/drm_gem_vram_helper.c:564 >>> bo_driver_move_notify+0x8c/0x98 >> >> A total shot in the dark. This might make no sense, >> but it's worth a try: > > Thanks for the suggestion, but still the same splat. > > I haven't had a chance to analyze the problem myself. But perhaps we > should just change over the device-managed interface, as Daniel mentioned. > >> >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c >> b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c >> index 2fd4ca91a62d..69bb0e29da88 100644 >> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c >> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c >> @@ -247,9 +247,8 @@ static int hibmc_unload(struct drm_device *dev) >>   { >>          struct hibmc_drm_private *priv = dev->dev_private; >> -       hibmc_fbdev_fini(priv); >> - >>          drm_atomic_helper_shutdown(dev); >> +       hibmc_fbdev_fini(priv); >>          if (dev->irq_enabled) >>                  drm_irq_uninstall(dev); >> >> Hope it helps, >> Ezequiel >> > > Thanks, > John > > [EOM] > >>> [   27.798969] Modules linked in: >>> [   27.802018] CPU: 24 PID: 1 Comm: swapper/0 Tainted: G    B >>>    5.5.0-rc1-dirty #565 >>> [   27.810358] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI >>> RC0 - V1.16.01 03/15/2019 >>> [   27.818872] pstate: 20c00009 (nzCv daif +PAN +UAO) >>> [   27.823654] pc : bo_driver_move_notify+0x8c/0x98 >>> [   27.828262] lr : bo_driver_move_notify+0x40/0x98 >>> [   27.832868] sp : ffff00236f0677e0 >>> [   27.836173] x29: ffff00236f0677e0 x28: ffffa0001454e5e0 >>> [   27.841476] x27: ffff002366e52128 x26: ffffa000149e67b0 >>> [   27.846779] x25: ffff002366e523e0 x24: ffff002336936120 >>> [   27.852082] x23: ffff0023346f4010 x22: ffff002336936128 >>> [   27.857385] x21: ffffa000149c15c0 x20: ffff0023369361f8 >>> [   27.862687] x19: ffff002336936000 x18: 0000000000001258 >>> [   27.867989] x17: 0000000000001190 x16: 00000000000011d0 >>> [   27.873292] x15: 0000000000001348 x14: ffffa00012d68190 >>> [   27.878595] x13: 0000000000000006 x12: 1ffff40003241f91 >>> [   27.883897] x11: ffff940003241f91 x10: dfffa00000000000 >>> [   27.889200] x9 : ffff940003241f92 x8 : 0000000000000001 >>> [   27.894502] x7 : ffffa0001920fc88 x6 : ffff940003241f92 >>> [   27.899804] x5 : ffff940003241f92 x4 : ffff0023369363a0 >>> [   27.905107] x3 : ffffa00010c104b8 x2 : dfffa00000000000 >>> [   27.910409] x1 : 0000000000000003 x0 : 0000000000000001 >>> [   27.915712] Call trace: >>> [   27.918151]  bo_driver_move_notify+0x8c/0x98 >>> [   27.922412]  ttm_bo_cleanup_memtype_use+0x54/0x100 >>> [   27.927194]  ttm_bo_put+0x3a0/0x5d0 >>> [   27.930673]  drm_gem_vram_object_free+0xc/0x18 >>> [   27.935109]  drm_gem_object_free+0x34/0xd0 >>> [   27.939196]  drm_gem_object_put_unlocked+0xc8/0xf0 >>> [   27.943978]  hibmc_user_framebuffer_destroy+0x20/0x40 >>> [   27.949020]  drm_framebuffer_free+0x48/0x58 >>> [   27.953194]  drm_mode_object_put.part.1+0x90/0xe8 >>> [   27.957889]  drm_mode_object_put+0x28/0x38 >>> [   27.961976]  hibmc_fbdev_fini+0x54/0x78 >>> [   27.965802]  hibmc_unload+0x2c/0xd0 >>> [   27.969281]  hibmc_pci_remove+0x2c/0x40 >>> [   27.973109]  pci_device_remove+0x6c/0x140 >>> [   27.977110]  really_probe+0x174/0x548 >>> [   27.980763]  driver_probe_device+0x7c/0x148 >>> [   27.984936]  device_driver_attach+0x94/0xa0 >>> [   27.989109]  __driver_attach+0xa8/0x110 >>> [   27.992935]  bus_for_each_dev+0xe8/0x158 >>> [   27.996849]  driver_attach+0x30/0x40 >>> [   28.000415]  bus_add_driver+0x234/0x2f0 >>> [   28.004241]  driver_register+0xbc/0x1d0 >>> [   28.008067]  __pci_register_driver+0xbc/0xd0 >>> [   28.012329]  hibmc_pci_driver_init+0x20/0x28 >>> [   28.016590]  do_one_initcall+0xb4/0x254 >>> [   28.020417]  kernel_init_freeable+0x27c/0x328 >>> [   28.024765]  kernel_init+0x10/0x118 >>> [   28.028245]  ret_from_fork+0x10/0x18 >>> [   28.031813] ---[ end trace 35a83b71b657878d ]--- >>> [   28.036503] ------------[ cut here ]------------ >>> [   28.041115] WARNING: CPU: 24 PID: 1 at >>> drivers/gpu/drm/drm_gem_vram_helper.c:40 >>> ttm_buffer_object_destroy+0x4c/0x80 >>> [   28.051537] Modules linked in: >>> [   28.054585] CPU: 24 PID: 1 Comm: swapper/0 Tainted: G    B   W >>>    5.5.0-rc1-dirty #565 >>> [   28.062924] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI >>> RC0 - V1.16.01 03/15/2019 >>> >>> [snip] >>> >>> Indeed, simply unbinding the device from the driver causes the same sort >>> of issue: >>> >>> root@(none)$ cd ./bus/pci/drivers/hibmc-drm/ >>> root@(none)$ ls >>> 0000:05:00.0  bind          new_id        remove_id     uevent >>> unbind >>> root@(none)$ echo 0000\:05\:00.0 > unbind >>> [  116.074352] ------------[ cut here ]------------ >>> [  116.078978] WARNING: CPU: 17 PID: 1178 at >>> drivers/gpu/drm/drm_gem_vram_helper.c:40 >>> ttm_buffer_object_destroy+0x4c/0x80 >>> [  116.089661] Modules linked in: >>> [  116.092711] CPU: 17 PID: 1178 Comm: sh Tainted: G    B   W >>> 5.5.0-rc1-dirty #565 >>> [  116.100704] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI >>> RC0 - V1.16.01 03/15/2019 >>> [  116.109218] pstate: 20400009 (nzCv daif +PAN -UAO) >>> [  116.114001] pc : ttm_buffer_object_destroy+0x4c/0x80 >>> [  116.118956] lr : ttm_buffer_object_destroy+0x18/0x80 >>> [  116.123910] sp : ffff0022e6cef8e0 >>> [  116.127215] x29: ffff0022e6cef8e0 x28: ffff00231b1fb000 >>> [  116.132519] x27: 0000000000000000 x26: ffff00231b1fb000 >>> [  116.137821] x25: ffff0022e6cefdc0 x24: 0000000000002480 >>> [  116.143124] x23: ffff0023682b6ab0 x22: ffff0023682b6800 >>> [  116.148427] x21: ffff0023682b6800 x20: 0000000000000000 >>> [  116.153730] x19: ffff0023682b6800 x18: 0000000000000000 >>> [  116.159032] x17: 000000000000000000000000001 >>> [  116.185545] x7 : ffff0023682b6b07 x6 : ffff80046d056d61 >>> [  116.190848] x5 : ffff80046d056d61 x4 : ffff0023682b6ba0 >>> [  116.196151] x3 : ffffa00010197338 x2 : dfffa00000000000 >>> [  116.201453] x1 : 0000000000000003 x0 : 0000000000000001 >>> [  116.206756] Call trace: >>> [  116.209195]  ttm_buffer_object_destroy+0x4c/0x80 >>> [  116.213803]  ttm_bo_release_list+0x184/0x220 >>> [  116.218064]  ttm_bo_put+0x410/0x5d0 >>> [  116.221544]  drm_gem_vram_object_free+0xc/0x18 >>> [  116.225979]  drm_gem_object_free+0x34/0xd0 >>> [  116.230066]  drm_gem_object_put_unlocked+0xc8/0xf0 >>> [  116.234848]  hibmc_user_framebuffer_destroy+0x20/0x40 >>> [  116.239890]  drm_framebuffer_free+0x48/0x58 >>> [  116.244064]  drm_mode_object_put.part.1+0x90/0xe8 >>> [  116.248759]  drm_mode_object_put+0x28/0x38 >>> [  116.252846]  hibmc_fbdev_fini+0x54/0x78 >>> [  116.256672]  hibmc_unload+0x2c/0xd0 >>> [  116.260151]  hibmc_pci_remove+0x2c/0x40 >>> [  116.263979]  pci_device_remove+0x6c/0x140 >>> [  116.267980]  device_release_driver_internal+0x134/0x250 >>> [  116.273196]  device_driver_detach+0x28/0x38 >>> [  116.277369]  unbind_store+0xfc/0x150 >>> [  116.280934]  drv_attr_store+0x48/0x60 >>> [  116.284589]  sysfs_kf_write+0x80/0xb0 >>> [  116.288241]  kernfs_fop_write+0x1d4/0x320 >>> [  116.292243]  __vfs_write+0x54/0x98 >>> [  116.295635]  vfs_write+0xe8/0x270 >>> [  116.298940]  ksys_write+0xc8/0x180 >>> [  116.302333]  __arm64_sys_write+0x40/0x50 >>> [  116.306248]  el0_svc_common.constprop.0+0xa4/0x1f8 >>> [  116.311029]  el0_svc_handler+0x34/0xb0 >>> [  116.314770]  el0_sync_handler+0x10c/0x1c8 >>> [  116.318769]  el0_sync+0x140/0x180 >>> [  116.322074] ---[ end trace e60e43d0e316b5c8 ]--- >>> [  116.326868] ------------[ cut here ]------------ >>> >>> >>> dmesg and .config is here: >>> https://pastebin.com/4P5yaZBS >>> >>> I'm not sure if this is a HIBMC driver issue or issue with the >>> framework. >>> >>> john >>> >>> >>> _______________________________________________ >>> dri-devel mailing list >>> dri-devel@lists.freedesktop.org >>> https://lists.freedesktop.org/mailman/listinfo/dri-devel >> >> > > _______________________________________________ > Linuxarm mailing list > Linuxarm@huawei.com > http://hulk.huawei.com/mailman/listinfo/linuxarm > .