Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <525bc794-b797-9a53-7f59-debcfca9edd8@suse.com>
Date:   Tue, 18 Jul 2023 11:18:25 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.12.0
Subject: Re: [PATCH v2] usb: xhci: tegra: Add shutdown callback for Tegra XUSB
Content-Language: en-US
To:     Haotien Hsu <haotienh@nvidia.com>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Wayne Chang <waynec@nvidia.com>, JC Kuo <jckuo@nvidia.com>,
        WK Tsai <wtsai@nvidia.com>, Henry Lin <henryl@nvidia.com>
References: <20230718091425.307589-1-haotienh@nvidia.com>
From:   Oliver Neukum <oneukum@suse.com>
In-Reply-To: <20230718091425.307589-1-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?ZklYSU1JNlpxR3FHd2VTbDl1bFhLUGFqT2w4UWcwYzRLYkY5QTNKZ2o5Slow?=
 =?utf-8?B?OTZzSDV0T1NlTkR6UWgzSkUxS3JuRWNNeithRzVod21rZG9pbkkwdXVUWXoz?=
 =?utf-8?B?ekhNOHlDYStjT1NlUnkzUk5ETEtkZTJJeGZObDFBT1JNa0JlMzlDdDBVNlNO?=
 =?utf-8?B?YkdGblVNVXlmcS9vSlZKTFdZbC9Ba0RpaVRReTlVUXpMcHZoczF4MWpTdFdF?=
 =?utf-8?B?bmFUcGczYmxWOGVkVzBEMzFzV21CT2FsVFZmUUNJZmoyc1ptWHFLVnIwUEkx?=
 =?utf-8?B?eGNaU1h6dWpEVnAva2gwckQxVTlmZllKYndCOVludnlqdVFLOGxqUk5ZM2pH?=
 =?utf-8?B?UllPbU1JUGJxeVpUNXR1V25oTU5IL2NWMlRhSHk1YnlCQ3RjaTNPWmF1cS9L?=
 =?utf-8?B?dWVWRjhVWXhvWXRENkZRSjJ4UGhvbVd5YTFlbXo0bXVDazJ0NVBUUmZjS3dk?=
 =?utf-8?B?MjI4S3FyL2dyNmdNUlhkNHAwc1B4blFBZHpkR1NGZkl2aGRJalhPUXBMaldl?=
 =?utf-8?B?NlMyV0tFZ3I1b2ExQUd6M0ZrWElQVURPOHc5M0ZGNS81eVBrcEtNYWhDZEM5?=
 =?utf-8?B?MW9VUTJDMVRPV1ppT1JXWWNvZmt4bjFEYWx2MGFDMnFqR2lXSGVsNFI0amxB?=
 =?utf-8?B?eEFhcmRMZStFWU44U3lqQktOM1NsM0IyYjFIQVk5SGJWOUV4ZHdNdXlCanBl?=
 =?utf-8?B?cEVLSzVNL0Q5R0Q5WEhlWHR6QVNOWkJDcHg5dkJQT2lUSllvK2RKYVZxc1Qv?=
 =?utf-8?B?RGpHaVdTc0k3VUxhR3ZEUjRSMVR6dTAzWnNkVnBSS29BaUkyYXVaWCtaUWsx?=
 =?utf-8?B?Rjg3a1ZUUlpaRnExa2ZEenNBOGM4QlpLdWtQYXRLWFJJZHA4OFZ2VFBHaDNI?=
 =?utf-8?B?OFV5eUlZa2tmSUJ3M0RTV3RSM2NnclB3MG5hMXhZQ3N2UEk5bXJhWDArS3VR?=
 =?utf-8?B?SHlyb3phOEVVM1NqZjlNR09TczlTQi84R1huWnZDbWVZWFdwMWt3aTlBbkN4?=
 =?utf-8?B?SDB5cnJFS1pHNGt6Yk13VWVySWx1aElGcGgxcUppTGhLOXdBNWFmWFJEMHBH?=
 =?utf-8?B?aEhwYklhVGgzR2JzMmwrTEdraFg0VVdrWmdDcXJ4YjJkQ3VLUmdkc0ltTDNo?=
 =?utf-8?B?bytDSENqTjdTQytMUHpWTnZBbVBDTEQ1N3FKc0NuVk9TSFAxUFFVTDJta2VW?=
 =?utf-8?B?RmNCU0FUKzJFaDJjTlhMRVhaK1I1WW5UU3ZRbDdjZVViQXNLSWJSd09mb3Bt?=
 =?utf-8?B?ZmRTa2E3OGFuSGRlVW5aWmVIaG1PdmhvZDNKRzdBVzU4bDJIc2VTdlFMRjdi?=
 =?utf-8?B?ckVUdllCYzBIV1ZtS3krMldPT01xK2dxaERLYUpNeGNMa0s5bXpmeHB0MitL?=
 =?utf-8?B?dDFvT2sxcWFYK0RrcUwvRWF6SkdIY1FBdkpha1VLdDRDa0VTTUdjeTZsVnhC?=
 =?utf-8?B?ZzNMdk1nWG9taElqRkRpbTRvSHZBMy9mOC9abkQ0RFI0ZEg2WHBaS3AvUzBW?=
 =?utf-8?B?SDNwZXJib0VHRDNOc29BaXh2d2RVMERXSlRjSHcvTWo4TEcvV28vTkp0VEdW?=
 =?utf-8?B?V3VmOCtrQUtsaGRJdUR3NU1mNU5vUk9abFp2WDN5b2p4RTZaQW52eGxBajZU?=
 =?utf-8?B?NzZCTDhEL2o4bWhCNkdJbFdybkd4QVdycU1sNGdWRlptSW1wS01zdTIzclFI?=
 =?utf-8?B?TlgxTW1uSUdKaXZxNDdYL1RseDNSaktFbUxIMS8yY3BiVUZDcE93QUFrZnBO?=
 =?utf-8?B?UmM4YnV3NWt1YisvUDd2bGQ2bGxpQ2YrQTNycWFhaGpPalMwRjNsK3NqU0xq?=
 =?utf-8?B?bHlXR002NmRySG1RdU1wNDZqKy9pNmpjOFREVTFqMm5ycSt4NkpPckRINk9G?=
 =?utf-8?B?TjQ1ZGtCYXM2UXVqcE44Q0hEVi9JaDNLUy9VeW9KNEtIL1M1aE5DdHlFejJ4?=
 =?utf-8?B?RHZDN2g2eWVNanNWYzVQeWlKSU1lWjMwSTJ2R2FoaDM1cTV4SUFnT1hvcXVs?=
 =?utf-8?B?NGEzQjBsaTJQUGU0bVp1a3lTUVc1dFplbGNNM3NMWTQ4Y2k1OG4vVFNLSE96?=
 =?utf-8?B?UmhzUExybjJ2ODNMQmYwVVFtRVZWeWdwTWdoTEUyZE5jWjU5U1RTdkt0YnJC?=
 =?utf-8?B?T3RiOTRBaVl0cWkvRGo1T2dvbDRCTHRpdGRYK3lMdzE2U2p1Si84dnprKy8z?=
 =?utf-8?Q?DSywGBd0E4Ji1YUIJEQXcSM=3D?=
X-OriginatorOrg: suse.com
X-MS-Exchange-CrossTenant-Network-Message-Id: a1010adc-bc6d-4c3a-0753-08db876ff2c2
X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB7104.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Jul 2023 09:18:28.8661
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: /3U4iBQXIl0/QMY4v0K0syKto5C8jYBvMdLsNQYV6jU4TlG4YEtJF6S3YYLu85PDnfy551WGNQnl40XJ2gXzPQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM8PR04MB7764
X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,
        RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,
        T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 18.07.23 11:14, Haotien Hsu wrote:
> From: Henry Lin <henryl@nvidia.com>
> 
> If memory accesses by the Tegra XUSB controller are translated through
> the SMMU (System MMU), the hardware may continue accessing memory even
> after the SMMU translations have been disabled during the shutdown
> process and this can in turn cause unpredictable crashes.
> Fix this by adding a shutdown implementation that ensures the hardware
> is turned off during system reboot or shutdown.
> 
> Signed-off-by: Henry Lin <henryl@nvidia.com>
> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
> Acked-by: Thierry Reding <treding@nvidia.com>
> 
> ---
> V1 -> V2: Resend for the typo in the mailing list
> ---
>   drivers/usb/host/xhci-tegra.c | 28 +++++++++++++++++++++-------
>   1 file changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
> index a56cc81b9404..6ef2eac9835d 100644
> --- a/drivers/usb/host/xhci-tegra.c
> +++ b/drivers/usb/host/xhci-tegra.c
> @@ -1925,6 +1925,15 @@ static int tegra_xusb_probe(struct platform_device *pdev)
>   	return err;
>   }
>   
> +static void tegra_xusb_disable(struct tegra_xusb *tegra)
> +{
> +	tegra_xusb_powergate_partitions(tegra);
> +	tegra_xusb_powerdomain_remove(tegra->dev, tegra);
> +	tegra_xusb_phy_disable(tegra);
> +	tegra_xusb_clk_disable(tegra);
> +	regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
> +}
> +
>   static int tegra_xusb_remove(struct platform_device *pdev)
>   {
>   	struct tegra_xusb *tegra = platform_get_drvdata(pdev);
> @@ -1947,18 +1956,22 @@ static int tegra_xusb_remove(struct platform_device *pdev)
>   
>   	pm_runtime_put(&pdev->dev);
>   
> -	tegra_xusb_powergate_partitions(tegra);
> -
> -	tegra_xusb_powerdomain_remove(&pdev->dev, tegra);
> -
> -	tegra_xusb_phy_disable(tegra);
> -	tegra_xusb_clk_disable(tegra);
> -	regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
> +	tegra_xusb_disable(tegra);
>   	tegra_xusb_padctl_put(tegra->padctl);
>   
>   	return 0;
>   }
>   
> +static void tegra_xusb_shutdown(struct platform_device *pdev)
> +{
> +	struct tegra_xusb *tegra = platform_get_drvdata(pdev);
> +
> +	pm_runtime_get_sync(&pdev->dev);

Where is this balanced?

	Regards
		Oliver