From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-serial@vger.kernel.org,
"Greg KH" <gregkh@linuxfoundation.org>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] serial: 8250_dw: Take port lock while accessing LSR
Date: Wed, 15 Jun 2022 12:06:50 +0300 [thread overview]
Message-ID: <20220615090651.15340-3-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20220615090651.15340-1-ilpo.jarvinen@linux.intel.com>
Accessing LSR requires port lock because it mutates lsr_saved_flags
in serial_lsr_in().
Fixes: 197eb5c416ff ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
drivers/tty/serial/8250/8250_dw.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 4cc69bb612ab..f67fad3233e9 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -266,7 +266,10 @@ static int dw8250_handle_irq(struct uart_port *p)
/* Manually stop the Rx DMA transfer when acting as flow controller */
if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
+ spin_lock_irqsave(&p->lock, flags);
status = serial_lsr_in(up);
+ spin_unlock_irqrestore(&p->lock, flags);
+
if (status & (UART_LSR_DR | UART_LSR_BI)) {
dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
dw8250_writel_ext(p, DW_UART_DMASA, 1);
--
2.30.2
next prev parent reply other threads:[~2022-06-15 9:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-15 9:06 [PATCH 0/3] Serial: Two concurrency fixes & one related cleanup Ilpo Järvinen
2022-06-15 9:06 ` [PATCH 1/3] serial: 8250: Fix __stop_tx() & DMA Tx restart races Ilpo Järvinen
2022-06-15 9:06 ` Ilpo Järvinen [this message]
2022-06-15 10:07 ` [PATCH 2/3] serial: 8250_dw: Take port lock while accessing LSR Andy Shevchenko
2022-06-15 10:29 ` Ilpo Järvinen
2022-06-27 12:49 ` Greg KH
2022-06-15 9:06 ` [PATCH 3/3] serial: 8250_dma: No need for if (dma->tx_err) Ilpo Järvinen
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