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Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v2] USB: serial: xr: Add TIOCGRS485 and TIOCSRS485 ioctls Content-Language: en-US To: Jarkko Sonninen , Oliver Neukum Cc: Johan Hovold , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230313082734.886890-1-kasper@iki.fi> <3c53eca1-ce62-e98d-ee52-269a09480658@iki.fi> From: Oliver Neukum In-Reply-To: <3c53eca1-ce62-e98d-ee52-269a09480658@iki.fi> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: FR2P281CA0087.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:9b::6) To VI1PR04MB7104.eurprd04.prod.outlook.com (2603:10a6:800:126::9) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: VI1PR04MB7104:EE_|PAXPR04MB8427:EE_ X-MS-Office365-Filtering-Correlation-Id: 74fced05-bc14-4282-c2e3-08db23b5e6ee X-LD-Processed: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba,ExtFwd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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Would it be better to store only that to state ? > > Do I need locking at all in that case ? > > The whole struct is stored just in case, if someone would implement other functionality later. Well, 1. would you be happy if you were the one to implement additional features and found that you'd have to reinvent locking? 2. That would mean discarding the values given for delay_rts_before_send and delay_rts_after_send. That wouldn't be nice. It seems to me that all our algorithmic complexity goes away if you just turn "lock" into a mutex and just take it. Regards Oliver