serial: sh-sci: consider DR (data ready) bit adequately

To allow operation with a higher RX FIFO interrupt threshold in PIO
mode, it is necessary to consider the DR bit ("FIFO not full, but no
data received for 1.5 frames") as an indicator that data can be read.
Otherwise the driver will let data rot in the FIFO until the threshold
is reached.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.h b/drivers/tty/serial/sh-sci.h
index 30b6d67867e7f2cb75503f125270b154d194642f..971b2ab088d847af9d3d2b4e4c0c2dd820eee653 100644 (file)
--- a/drivers/tty/serial/sh-sci.h
+++ b/drivers/tty/serial/sh-sci.h
@@ -151,7 +151,7 @@ enum {
 #define SCCKS_XIN      BIT(14) /* SC_CLK uses bus clock (1) or SCIF_CLK (0) */
 
 #define SCxSR_TEND(port)       (((port)->type == PORT_SCI) ? SCI_TEND   : SCIF_TEND)
-#define SCxSR_RDxF(port)       (((port)->type == PORT_SCI) ? SCI_RDRF   : SCIF_RDF)
+#define SCxSR_RDxF(port)       (((port)->type == PORT_SCI) ? SCI_RDRF   : SCIF_DR | SCIF_RDF)
 #define SCxSR_TDxE(port)       (((port)->type == PORT_SCI) ? SCI_TDRE   : SCIF_TDFE)
 #define SCxSR_FER(port)                (((port)->type == PORT_SCI) ? SCI_FER    : SCIF_FER)
 #define SCxSR_PER(port)                (((port)->type == PORT_SCI) ? SCI_PER    : SCIF_PER)