This is a note to let you know that I've just added the patch titled
serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-pl011-do-not-clear-rx-fifo-rx-interrupt-in-un.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 32814ba5886fefcef2b086f1b17cefc986902fb9
Author: delisun <delisun@xxxxxxxxxxxx>
Date: Thu Nov 10 10:01:08 2022 +0800
serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
[ 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 <delisun@xxxxxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221110020108.7700-1-delisun@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 72c2a978cf61..c211a1e92db7 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1831,8 +1831,17 @@ 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)
