From 95c1bb8485b7d981d6359842ddfaedc7b540d005 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 28 Jun 2022 12:01:28 +0300 Subject: [PATCH] serial: 8250_dw: Take port lock while accessing LSR MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Accessing LSR requires port lock because it mutates lsr_saved_flags in serial_lsr_in(). Fixes: 7895b0005f82 ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()") Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/c5879db7-bee9-93f-526e-872a292442@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- 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 167a691c7b197..f78b13db1b1e2 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); -- 2.39.5