mirror of
https://github.com/OpenVoiceOS/OpenVoiceOS
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75 lines
3.0 KiB
Diff
75 lines
3.0 KiB
Diff
From 15d8a9cc288fb357d7e88d18443499acc485a8f3 Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:43:25 +0206
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Subject: [PATCH 034/196] serial: 8250_dw: Use port lock wrappers
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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When a serial port is used for kernel console output, then all
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modifications to the UART registers which are done from other contexts,
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e.g. getty, termios, are interference points for the kernel console.
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So far this has been ignored and the printk output is based on the
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principle of hope. The rework of the console infrastructure which aims to
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support threaded and atomic consoles, requires to mark sections which
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modify the UART registers as unsafe. This allows the atomic write function
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to make informed decisions and eventually to restore operational state. It
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also allows to prevent the regular UART code from modifying UART registers
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while printk output is in progress.
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All modifications of UART registers are guarded by the UART port lock,
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which provides an obvious synchronization point with the console
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infrastructure.
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To avoid adding this functionality to all UART drivers, wrap the
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spin_[un]lock*() invocations for uart_port::lock into helper functions
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which just contain the spin_[un]lock*() invocations for now. In a
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subsequent step these helpers will gain the console synchronization
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mechanisms.
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Converted with coccinelle. No functional change.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-9-john.ogness@linutronix.de
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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drivers/tty/serial/8250/8250_dw.c | 8 ++++----
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1 file changed, 4 insertions(+), 4 deletions(-)
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diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
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index a1f2259cc9a9..53c284bb271d 100644
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--- a/drivers/tty/serial/8250/8250_dw.c
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+++ b/drivers/tty/serial/8250/8250_dw.c
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@@ -263,20 +263,20 @@ static int dw8250_handle_irq(struct uart_port *p)
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* so we limit the workaround only to non-DMA mode.
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*/
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if (!up->dma && rx_timeout) {
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- spin_lock_irqsave(&p->lock, flags);
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+ uart_port_lock_irqsave(p, &flags);
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status = serial_lsr_in(up);
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if (!(status & (UART_LSR_DR | UART_LSR_BI)))
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(void) p->serial_in(p, UART_RX);
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- spin_unlock_irqrestore(&p->lock, flags);
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+ uart_port_unlock_irqrestore(p, flags);
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}
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/* Manually stop the Rx DMA transfer when acting as flow controller */
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if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
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- spin_lock_irqsave(&p->lock, flags);
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+ uart_port_lock_irqsave(p, &flags);
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status = serial_lsr_in(up);
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- spin_unlock_irqrestore(&p->lock, flags);
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+ uart_port_unlock_irqrestore(p, flags);
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if (status & (UART_LSR_DR | UART_LSR_BI)) {
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dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
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--
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2.45.1
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