From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 37B1F339861 for ; Fri, 5 Jun 2026 18:31:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684279; cv=none; b=gjSPQx7HrlsKWT1Hl3hpj+Eglgttn91VMbxKOGDnps7lvNg+tmj3C4MxrmQnOqbfORoJ6VrldAc5vMWfOgDYBRJ1UrnFwp7KEvKzjsHnaYfPwd9H3YXHTrwfmVydAI0tZrz3JqYjMeI5yc6XpCPuw/X1uG+WhzCJsL876oExjaM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684279; c=relaxed/simple; bh=ECV/v1J/b5B5Hb+cn1DynBjA8ex97xO3uik7PpIVhig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hBl7C4/HgobZ1h7L/MKgpeu+drBeFL984gLRFxUwJLeTXgH3/tq/U4r1gF2WMktYwenpgF4mcorVjE1sJxOXHNdMXM6PYwBznrdZp8Yf/O7rGDhGeC5rNgJXSq/CWsdKmBzcaKWuaTpwYTbS/7DSUr5AuxkBwis1y/5VMf+8Pxk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cs40CsCP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cs40CsCP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B1B91F00893; Fri, 5 Jun 2026 18:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780684277; bh=izpKdTq+KeZbgIAPo90DjZXLqlv7FY9l8eBSAucksRQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cs40CsCPROB2EnTr0TlOlX4O813T5iGKCsnLv0jQGwlTsdDwuoljk9K9/+3Oxl9FJ aQTCeb3KeSfd8gK4cdlKbbt4QK/qxuvtl+3ZDAqrUG/MYWyKu5p+KFdHUjjcaZH2rl BAGmPXy6fKUfLS2TmPOQIZnc4QS4gx5gQSKY7ko0MnijtKGd2x+SxhnHndpITyoF5X P/gQdK20VA1uzFJjhpeg9wvXZj1BFhBw7BokWlu0k/SibSvYb9emCCVELcEP+uPy36 NetgErBx9Mk4RaesLmhPWFx/hAoG4IM5HRll2RSXr+UYPTGQDOUW6/ekYGw5wzINsa iRgEPM7d1dkvA== From: Sasha Levin To: stable@vger.kernel.org Cc: Thomas Gleixner , John Ogness , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 5.15.y 1/3] serial: samsung_tty: Use port lock wrappers Date: Fri, 5 Jun 2026 14:31:13 -0400 Message-ID: <20260605183115.2054750-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026060429-saddling-hacked-b97c@gregkh> References: <2026060429-saddling-hacked-b97c@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Thomas Gleixner [ Upstream commit 97d7a9aeba1d424c2359f1686d02c75d798ad184 ] When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20230914183831.587273-54-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman Stable-dep-of: a3bb136bff5e ("tty: serial: samsung: Remove redundant port lock acquisition in rx helpers") Signed-off-by: Sasha Levin --- drivers/tty/serial/samsung_tty.c | 44 ++++++++++++++++---------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 7d3630ddebb39e..5f05336b448599 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -246,7 +246,7 @@ static void s3c24xx_serial_rx_enable(struct uart_port *port) unsigned int ucon, ufcon; int count = 10000; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); while (--count && !s3c24xx_serial_txempty_nofifo(port)) udelay(100); @@ -260,7 +260,7 @@ static void s3c24xx_serial_rx_enable(struct uart_port *port) wr_regl(port, S3C2410_UCON, ucon); ourport->rx_enabled = 1; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c24xx_serial_rx_disable(struct uart_port *port) @@ -269,14 +269,14 @@ static void s3c24xx_serial_rx_disable(struct uart_port *port) unsigned long flags; unsigned int ucon; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ucon = rd_regl(port, S3C2410_UCON); ucon &= ~S3C2410_UCON_RXIRQMODE; wr_regl(port, S3C2410_UCON, ucon); ourport->rx_enabled = 0; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c24xx_serial_stop_tx(struct uart_port *port) @@ -344,7 +344,7 @@ static void s3c24xx_serial_tx_dma_complete(void *args) dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); port->icount.tx += count; @@ -354,7 +354,7 @@ static void s3c24xx_serial_tx_dma_complete(void *args) uart_write_wakeup(port); s3c24xx_serial_start_next_tx(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void enable_tx_dma(struct s3c24xx_uart_port *ourport) @@ -620,7 +620,7 @@ static void s3c24xx_serial_rx_dma_complete(void *args) received = dma->rx_bytes_requested - state.residue; async_tx_ack(dma->rx_desc); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); if (received) s3c24xx_uart_copy_rx_to_tty(ourport, t, received); @@ -632,7 +632,7 @@ static void s3c24xx_serial_rx_dma_complete(void *args) s3c64xx_start_rx_dma(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport) @@ -723,7 +723,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id) utrstat = rd_regl(port, S3C2410_UTRSTAT); rd_regl(port, S3C2410_UFSTAT); - spin_lock(&port->lock); + uart_port_lock(port); if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) { s3c64xx_start_rx_dma(ourport); @@ -752,7 +752,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id) wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT); finish: - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @@ -849,9 +849,9 @@ static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id) struct s3c24xx_uart_port *ourport = dev_id; struct uart_port *port = &ourport->port; - spin_lock(&port->lock); + uart_port_lock(port); s3c24xx_serial_rx_drain_fifo(ourport); - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @@ -933,11 +933,11 @@ static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id) struct s3c24xx_uart_port *ourport = id; struct uart_port *port = &ourport->port; - spin_lock(&port->lock); + uart_port_lock(port); s3c24xx_serial_tx_chars(ourport); - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @@ -1025,7 +1025,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state) unsigned long flags; unsigned int ucon; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ucon = rd_regl(port, S3C2410_UCON); @@ -1036,7 +1036,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state) wr_regl(port, S3C2410_UCON, ucon); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) @@ -1295,7 +1295,7 @@ static int s3c64xx_serial_startup(struct uart_port *port) ourport->rx_enabled = 1; ourport->tx_enabled = 0; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ufcon = rd_regl(port, S3C2410_UFCON); ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8; @@ -1305,7 +1305,7 @@ static int s3c64xx_serial_startup(struct uart_port *port) enable_rx_pio(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); /* Enable Rx Interrupt */ s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM); @@ -1333,7 +1333,7 @@ static int apple_s5l_serial_startup(struct uart_port *port) ourport->rx_enabled = 1; ourport->tx_enabled = 0; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ufcon = rd_regl(port, S3C2410_UFCON); ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8; @@ -1343,7 +1343,7 @@ static int apple_s5l_serial_startup(struct uart_port *port) enable_rx_pio(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); /* Enable Rx Interrupt */ s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON); @@ -1644,7 +1644,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, ulcon |= S3C2410_LCON_PNONE; } - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); dev_dbg(port->dev, "setting ulcon to %08x, brddiv to %d, udivslot %08x\n", @@ -1702,7 +1702,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= RXSTAT_DUMMY_READ; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static const char *s3c24xx_serial_type(struct uart_port *port) -- 2.53.0