From 926b0967f781a04e1a1f4c50f66fb05b0743dd61 Mon Sep 17 00:00:00 2001 From: delisun Date: Thu, 10 Nov 2022 10:01:08 +0800 Subject: [PATCH] serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit 032d5a71ed378ffc6a2d41a187d8488a4f9fe415 ] Clearing the RX FIFO will cause data loss. Copy the pl011_enabl_interrupts implementation, and remove the clear interrupt and FIFO part of the code. Fixes: 211565b10099 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle") Signed-off-by: delisun Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221110020108.7700-1-delisun@pateo.com.cn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/amba-pl011.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index ca105e9..7c8515f 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1836,8 +1836,17 @@ static void pl011_enable_interrupts(struct uart_amba_port *uap) static void pl011_unthrottle_rx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); + unsigned long flags; - pl011_enable_interrupts(uap); + spin_lock_irqsave(&uap->port.lock, flags); + + uap->im = UART011_RTIM; + if (!pl011_dma_rx_running(uap)) + uap->im |= UART011_RXIM; + + pl011_write(uap->im, uap, REG_IMSC); + + spin_unlock_irqrestore(&uap->port.lock, flags); } static int pl011_startup(struct uart_port *port) -- 2.7.4