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([154.83.84.229]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ab0458bce8sm1163556a91.3.2026.10.08.05.06.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Oct 2026 05:06:20 -0700 (PDT) From: Kun Luo To: Mathias Nyman Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu , Kun Luo Subject: [PATCH] xhci: dbgtty: convert rx push tasklet to BH workqueue Date: Thu, 8 Oct 2026 20:06:05 +0800 Message-ID: <20261008120605.174601-1-luokun485@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The kernel is converting remaining tasklet users to BH workqueues so softirq handling can go through the workqueue path. The dbc TTY rx push path is a straightforward bottom-half: schedule from IRQ / unthrottle, run the same work, kill on port teardown. Replace the tasklet with system_bh_wq. Behavior stays in softirq context, so existing locking is unchanged. Compile-tested only. Signed-off-by: Kun Luo --- drivers/usb/host/xhci-dbgcap.h | 2 +- drivers/usb/host/xhci-dbgtty.c | 17 +++++++++-------- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h index 5b18efb2c1ea..78e9b5e674a3 100644 --- a/drivers/usb/host/xhci-dbgcap.h +++ b/drivers/usb/host/xhci-dbgcap.h @@ -127,7 +127,7 @@ struct dbc_port { struct list_head read_pool; struct list_head read_queue; unsigned int n_read; - struct tasklet_struct push; + struct work_struct push; struct list_head write_pool; unsigned int tx_boundary; diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c index 3d51e8d82659..c18215751d92 100644 --- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "xhci.h" #include "xhci-dbgcap.h" @@ -189,9 +190,9 @@ dbc_read_complete(struct xhci_dbc *dbc, struct dbc_request *req) } } - /* defer moving data from req to tty buffer to a tasklet */ + /* defer moving data from req to tty buffer to BH workqueue */ list_add_tail(&req->list_pool, &port->read_queue); - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); out: spin_unlock_irqrestore(&port->port_lock, flags); } @@ -384,7 +385,7 @@ static void dbc_tty_unthrottle(struct tty_struct *tty) unsigned long flags; spin_lock_irqsave(&port->port_lock, flags); - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); spin_unlock_irqrestore(&port->port_lock, flags); } @@ -400,13 +401,13 @@ static const struct tty_operations dbc_tty_ops = { .unthrottle = dbc_tty_unthrottle, }; -static void dbc_rx_push(struct tasklet_struct *t) +static void dbc_rx_push(struct work_struct *work) { struct dbc_request *req; struct tty_struct *tty; unsigned long flags; bool disconnect = false; - struct dbc_port *port = from_tasklet(port, t, push); + struct dbc_port *port = from_work(port, work, push); struct list_head *queue = &port->read_queue; int untransferred; @@ -438,7 +439,7 @@ static void dbc_rx_push(struct tasklet_struct *t) } if (!list_empty(queue)) - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); if (!disconnect) dbc_start_rx(port); @@ -467,7 +468,7 @@ xhci_dbc_tty_init_port(struct xhci_dbc *dbc, struct dbc_port *port) { tty_port_init(&port->port); spin_lock_init(&port->port_lock); - tasklet_setup(&port->push, dbc_rx_push); + INIT_WORK(&port->push, dbc_rx_push); INIT_LIST_HEAD(&port->read_pool); INIT_LIST_HEAD(&port->read_queue); INIT_LIST_HEAD(&port->write_pool); @@ -479,7 +480,7 @@ xhci_dbc_tty_init_port(struct xhci_dbc *dbc, struct dbc_port *port) static void xhci_dbc_tty_exit_port(struct dbc_port *port) { - tasklet_kill(&port->push); + cancel_work_sync(&port->push); tty_port_destroy(&port->port); } -- 2.54.0