serial: sh-sci: describe locking requirements for invalidating RXDMA

Make sure everyone knows that calling this function needs protection.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240506114016.30498-8-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 4d34950268b9cdd258382d4e2c80eccdd1922de3..7a7bc18e47055736442eabef80902ea1bb63c71b 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1257,6 +1257,7 @@ static int sci_dma_rx_find_active(struct sci_port *s)
        return -1;
 }
 
+/* Must only be called with uart_port_lock taken */
 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
 {
        unsigned int i;