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Mon, 11 May 2026 03:40:03 -0700 From: Vishwaroop A To: , CC: , , , , , Subject: [PATCH v4 0/2] spi: add new_device/delete_device sysfs interface Date: Mon, 11 May 2026 10:40:00 +0000 Message-ID: <20260511104002.976269-1-va@nvidia.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ1PEPF000023CE:EE_|CH2PR12MB4133:EE_ X-MS-Office365-Filtering-Correlation-Id: 23177a80-1db9-4b2a-8775-08deaf49afcd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|30052699003|1800799024|36860700016|376014|82310400026|56012099003|13003099007|18002099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230040)(30052699003)(1800799024)(36860700016)(376014)(82310400026)(56012099003)(13003099007)(18002099003);DIR:OUT;SFP:1101; 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Changes since v3: - Replaced holding add_lock across __spi_add_device() + list insertion (which caused an ABBA deadlock between add_lock and the kernfs active reference during concurrent unbind) with: * A 'dead' flag on spi_controller, set in spi_unregister_controller() under both add_lock and userspace_clients_lock. * __spi_add_device() checks ctlr->dead under add_lock to reject new devices after teardown begins. * new_device_store() checks ctlr->dead under userspace_clients_lock before list insertion, falling back to cleanup + ENODEV. * add_lock is released before device_del() so in-flight sysfs stores can drain without deadlocking. * get_device() taken before spi_add_device() prevents use-after-free if __unregister runs concurrently. - Used #if IS_ENABLED() preprocessor guard (not runtime IS_ENABLED()) for the ctlr->dead check in __spi_add_device(), since the dead field is conditionally compiled. Changes since v2: - Gated sysfs attributes and locking on CONFIG_SPI_DYNAMIC. Changes since v1: - Added locking to prevent races between new_device_store() and concurrent spi_unregister_controller(). Link: https://lore.kernel.org/linux-tegra/909f0c92-d110-4253-903e-5c81e21e12c9@nvidia.com/ Vishwaroop A (2): spi: add new_device/delete_device sysfs interface docs: spi: add documentation for userspace device instantiation .../ABI/testing/sysfs-class-spi-master | 34 +++ Documentation/spi/index.rst | 1 + Documentation/spi/instantiating-devices.rst | 88 +++++++ drivers/spi/spi.c | 216 +++++++++++++++++- include/linux/spi/spi.h | 13 + 5 files changed, 346 insertions(+), 6 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-class-spi-master create mode 100644 Documentation/spi/instantiating-devices.rst -- 2.17.1