Message-ID: <1a7bd64b-7d4e-61fc-797c-816a2fe8d83e@nvidia.com>
Date:   Tue, 21 Mar 2023 07:15:54 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.8.0
Subject: Re: [PATCH v3] usb: xhci: tegra: fix sleep in atomic call
To:     Haotien Hsu <haotienh@nvidia.com>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     JC Kuo <jckuo@nvidia.com>, Wayne Chang <waynec@nvidia.com>
References: <20230321071339.925636-1-haotienh@nvidia.com>
Content-Language: en-US
From:   Jon Hunter <jonathanh@nvidia.com>
In-Reply-To: <20230321071339.925636-1-haotienh@nvidia.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?c0R0L05heFFHK1dZN20xZnN6dzIzV2tndGlrby9RMitYUVptWGgzdFozaGxm?=
 =?utf-8?B?RCtTSnNxSUtDTGtxL2NWK01pOFNSZXcxL1lJeWZjdXo2ZEtGTUFnckpyUzVx?=
 =?utf-8?B?LzdyYUI3UTNpclB2WGt4c1hhcjVlTUZlblFLTlRoN0FIRWVjSUJ3L1JQdzNo?=
 =?utf-8?B?cWljOENITElvbGVXWGpzTzhxSGs4NGNpRW81RUdFOWxESVNWc21yelV1YXl3?=
 =?utf-8?B?SVMrbDJxbEdqTmtxZzB1aTNZU0FhQS9mUHpHMjlnSEZrNXF6V0ppTGg1N3hr?=
 =?utf-8?B?QnFCaVRtWTVObjZDTWJENGdaQmMrMTJyMXN3R214ejhzTzd1d2psSE9NRUh5?=
 =?utf-8?B?ekJsTWxWQk5WWXMwNWJyVjJCSk5kWEhvRTVPRnNUOUNWbENJdHRFcDl6dnFR?=
 =?utf-8?B?cDZQRC9qV09IS014VHY1Qng5am9zVU56b3FoTml0YUhEbkx0ZVdPQjBRa3dO?=
 =?utf-8?B?NHphbDYxVFd3TDB3eWFnaDVSeE5Ob0JtMWtnMCtHRXM5QTBBckZXRDNwakcy?=
 =?utf-8?B?NUgrSU1CQXR4QkJjaXhSekFTRXJVbTFmL05ENHloYkIwRStjVzVjWloybXlD?=
 =?utf-8?B?bFhkUkgxUDFqT0taRjM0LzhhQm1QanpqN2ZocytzdDlXZzJGQndNWlA4aHRx?=
 =?utf-8?B?YUE1Z0JCVmdwQlNkUEdhZWlWSm9PR1ZMQ2kxN3E3cDBWNkFMUXk1UmdQQUFu?=
 =?utf-8?B?b1R6RTJON3JkZnJyVGxXMHdkL1NnM20rWEhvTkZYUS9GQzJHbFQraGtWYzVa?=
 =?utf-8?B?dWZaY09vamtPSC9Ec0NCcTY4VDc2Nk1ycVA4d2E1ZkVKaUNRbjdvOHB3S3N5?=
 =?utf-8?B?bDRKRU40cU5sa2VDVEpyV3REN2dRRy9ZblRKTHZVZHp3cGUyY3g4OHFJd3hP?=
 =?utf-8?B?UzJvcFNRSy90U2Zudkk0S29HenVKZjRQNGVRYkRWd0xiOFV1V2FPYUpXYWF5?=
 =?utf-8?B?TjNFTG9SS08wcTUySnkzQnVPUFV5RE13bGY2d1c2ZmlCc2duQkg4N2RDRFFv?=
 =?utf-8?B?S2xYcEtNNWZIR0Z1c1cyclgwcDBadTlPblBDQjZ1NCs5UTltN0xTU1VwOW8z?=
 =?utf-8?B?cldlTW5hMUxNa2RQandQMm9ZMXhOQlVXZDV3TWM3YXkrcFY5M2ZBOXorc2c4?=
 =?utf-8?B?NW0zU3pPcWRxNzA0bHQ4dndJYUdRM0dEOU51R0FReXNlMFZYKzZBR0lJeklZ?=
 =?utf-8?B?eDZtL29yd2VjRDVjenkwdWR6OVc0RmRIeStWa3E4ci9VVWNWOTFBRy9KQml0?=
 =?utf-8?B?UjR2N1VtZWxnU0dDQnY5aE1xQ1pCNlRsb2NIMXpXVjdLZmw2Tzk1c2Q0WnJm?=
 =?utf-8?B?dTVPZ01vU0tMcE40ZGlqelczcUVNQ0VlV2dmNTV0UU5LZGNTa0wzYjdNcFJj?=
 =?utf-8?B?YVpiZDlyUmh1RHpxOWpEOWtkSnlvNGZIQ1prWm5ZRkNSNWF6Y3BVbmJhcDFF?=
 =?utf-8?B?RjFSbUxTNkNkK1NqNDdxcDRndFE3U1M5aHF3VG56MG50REV2YTV3SDNOdFJj?=
 =?utf-8?B?RDAweTFtdmZ0ZUZVWDJlaTM4RkJMd2Z1akw3Lzd1aHo0MHRmOEhUMEl5eG9B?=
 =?utf-8?B?TlJzY1lqNkJiU0NsWXhiM3VKMzlVbCsxNHFtcUhRK3RISjlGQjJxVEY0OGFV?=
 =?utf-8?B?MlRqZzh1emhZWTE2NksyNFdwcUx6dnlvcmJGei94dlRYSU1UOSthOHlYZU9k?=
 =?utf-8?B?Z281TkZ4UFh6ZE5keGF5WThSWm1tUUc1TitFdkQzZ2JVNVU1L2pwNjlNcmVh?=
 =?utf-8?B?T3V4cWI3MmdNVnVjWHdFdUJSS05DeUMzQlRvQnpHZVE4cSt3VmVkS1NabXVU?=
 =?utf-8?B?NnVwRWpVVklmVE1LUGVDUUc4dU9DbXVySXVTbDArYllVNUpMQkorNVlLT3BZ?=
 =?utf-8?B?a2xRVklGK3hlOUM5MlVTdXkzN2ZxMlpka2orRXRUN0hpZEoxVG1QellWTm5l?=
 =?utf-8?B?Z3VZMDMwUkZDWTlOZ01LVERuSldEQ2V4WFc0Q1Njdy9LL1BXeVo5U3ZZN1VO?=
 =?utf-8?B?VkszeFpEVDk2K1RaWkowOEZab0EyZWM3bzY1eWFvTzloaGQwWkdBTUphaGVO?=
 =?utf-8?B?SEx2amhqQnUxUDhNSTdJK3RZODgyTlozUTZwV3Rwd1F3RmoySlpwcVAzemtx?=
 =?utf-8?B?TEtJVlpWTUpYNEI2OW1JQ0hIQXBsYnFCSGRvbmZ6VnBmUEZ3QjFNdEV6cFhu?=
 =?utf-8?B?RHFwU3BBRzEweVZIOGZTMkhxbDRXN20yVXN3Um1BZS9OQnpZRlJGR0M0bll4?=
 =?utf-8?B?cm5xL09xTjI2RVpsRjlLUWxFMElBPT0=?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d8c7c2df-5e31-4122-3d85-08db29dc20f0
X-MS-Exchange-CrossTenant-AuthSource: CO6PR12MB5444.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Mar 2023 07:16:02.7560
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: YVnuO7VfKoZX/fGLJrayK+teyDqS5+B8c1UDwM3fHUgNOPtwqcIXa6qYsdHCy2we8V/jezsZ0Bnn0nKaG4T5aQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5105
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 21/03/2023 07:13, Haotien Hsu wrote:
> From: Wayne Chang <waynec@nvidia.com>
> 
> When we set the OTG port to Host mode, we observed the following splat:
> [  167.057718] BUG: sleeping function called from invalid context at
> include/linux/sched/mm.h:229
> [  167.057872] Workqueue: events tegra_xusb_usb_phy_work
> [  167.057954] Call trace:
> [  167.057962]  dump_backtrace+0x0/0x210
> [  167.057996]  show_stack+0x30/0x50
> [  167.058020]  dump_stack_lvl+0x64/0x84
> [  167.058065]  dump_stack+0x14/0x34
> [  167.058100]  __might_resched+0x144/0x180
> [  167.058140]  __might_sleep+0x64/0xd0
> [  167.058171]  slab_pre_alloc_hook.constprop.0+0xa8/0x110
> [  167.058202]  __kmalloc_track_caller+0x74/0x2b0
> [  167.058233]  kvasprintf+0xa4/0x190
> [  167.058261]  kasprintf+0x58/0x90
> [  167.058285]  tegra_xusb_find_port_node.isra.0+0x58/0xd0
> [  167.058334]  tegra_xusb_find_port+0x38/0xa0
> [  167.058380]  tegra_xusb_padctl_get_usb3_companion+0x38/0xd0
> [  167.058430]  tegra_xhci_id_notify+0x8c/0x1e0
> [  167.058473]  notifier_call_chain+0x88/0x100
> [  167.058506]  atomic_notifier_call_chain+0x44/0x70
> [  167.058537]  tegra_xusb_usb_phy_work+0x60/0xd0
> [  167.058581]  process_one_work+0x1dc/0x4c0
> [  167.058618]  worker_thread+0x54/0x410
> [  167.058650]  kthread+0x188/0x1b0
> [  167.058672]  ret_from_fork+0x10/0x20
> 
> The function tegra_xusb_padctl_get_usb3_companion eventually calls
> tegra_xusb_find_port and this in turn calls kasprintf which might sleep
> and so cannot be called from an atomic context.
> 
> Fix this by moving the call to tegra_xusb_padctl_get_usb3_companion to
> the tegra_xhci_id_work function where it is really needed.
> 
> Fixes: f836e7843036 ("usb: xhci-tegra: Add OTG support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Wayne Chang <waynec@nvidia.com>
> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
> ---
> V2 -> V3: Add version information
> V1 -> V2: Add "Fixes" and "Cc:" lines and update copyright years
> ---
> 
>   drivers/usb/host/xhci-tegra.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
> index 1ff22f675930..8dbce2cdb7e4 100644
> --- a/drivers/usb/host/xhci-tegra.c
> +++ b/drivers/usb/host/xhci-tegra.c
> @@ -2,7 +2,7 @@
>   /*
>    * NVIDIA Tegra xHCI host controller driver
>    *
> - * Copyright (c) 2014-2020, NVIDIA CORPORATION. All rights reserved.
> + * Copyright (c) 2014-2020,2023, NVIDIA CORPORATION. All rights reserved.

Please drop this from this patch. Greg indicated in V1, that this should 
not be part of this patch.

Jon

-- 
nvpublic