4.19-stable review patch. If anyone has any objections, please let me know.
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From: Wolfram Sang wsa+renesas@sang-engineering.com
[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ]
The to-be-fixed commit removed locking when invalidating the DMA RX descriptors on shutdown. It overlooked that there is still a rx_timer running which may still access the protected data. So, re-add the locking.
Reported-by: Dirk Behme dirk.behme@de.bosch.com Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO") Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineerin... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/sh-sci.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 8a7592cd1aff9..0a89fd43848df 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1261,9 +1261,14 @@ static void sci_dma_rx_chan_invalidate(struct sci_port *s) static void sci_rx_dma_release(struct sci_port *s) { struct dma_chan *chan = s->chan_rx_saved; + struct uart_port *port = &s->port; + unsigned long flags;
+ uart_port_lock_irqsave(port, &flags); s->chan_rx_saved = NULL; sci_dma_rx_chan_invalidate(s); + uart_port_unlock_irqrestore(port, flags); + dmaengine_terminate_sync(chan); dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0], sg_dma_address(&s->sg_rx[0]));