Commit f77ebb24 authored by Fugang Duan's avatar Fugang Duan Committed by Greg Kroah-Hartman
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tty: serial: fsl_lpuart: correct the FIFO depth size 



VF610/LS1021a/i.MX7ULP/i.MX8QXP reference manual describe the
TXFIFOSIZE/RXFIFOSIZE field as below.

000b - FIFO/Buffer depth = 1 dataword.
001b - FIFO/Buffer depth = 4 datawords.
010b - FIFO/Buffer depth = 8 datawords.
011b - FIFO/Buffer depth = 16 datawords.
100b - FIFO/Buffer depth = 32 datawords.
101b - FIFO/Buffer depth = 64 datawords.
110b - FIFO/Buffer depth = 128 datawords.
111b - FIFO/Buffer depth = 256 datawords. (Reserved for VF610)

So the FIFO depth should be: 0x1 << (val ? (val + 1) : 0)

Signed-off-by: default avatarFugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-6-fugang.duan@nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 638341d5

drivers/tty/serial/fsl_lpuart.c

+9 −10
Original line number Diff line number Diff line
@@ -214,6 +214,7 @@ 
#define UARTFIFO_TXSIZE_OFF	4

#define UARTFIFO_RXFE		0x00000008

#define UARTFIFO_RXSIZE_OFF	0

#define UARTFIFO_DEPTH(x)	(0x1 << ((x) ? ((x) + 1) : 0))



#define UARTWATER_COUNT_MASK	0xff

#define UARTWATER_TXCNT_OFF	8
@@ -1380,13 +1381,12 @@ static int lpuart_startup(struct uart_port *port) 
	/* determine FIFO size and enable FIFO mode */

	temp = readb(sport->port.membase + UARTPFIFO);



	sport->txfifo_size = 0x1 << (((temp >> UARTPFIFO_TXSIZE_OFF) &

		UARTPFIFO_FIFOSIZE_MASK) + 1);



	sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_TXSIZE_OFF) &

					    UARTPFIFO_FIFOSIZE_MASK);

	sport->port.fifosize = sport->txfifo_size;



	sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &

		UARTPFIFO_FIFOSIZE_MASK) + 1);

	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) &

					    UARTPFIFO_FIFOSIZE_MASK);



	spin_lock_irqsave(&sport->port.lock, flags);
@@ -1431,13 +1431,12 @@ static int lpuart32_startup(struct uart_port *port) 
	/* determine FIFO size */

	temp = lpuart32_read(&sport->port, UARTFIFO);



	sport->txfifo_size = 0x1 << (((temp >> UARTFIFO_TXSIZE_OFF) &

		UARTFIFO_FIFOSIZE_MASK) - 1);



	sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_TXSIZE_OFF) &

					    UARTFIFO_FIFOSIZE_MASK);

	sport->port.fifosize = sport->txfifo_size;



	sport->rxfifo_size = 0x1 << (((temp >> UARTFIFO_RXSIZE_OFF) &

		UARTFIFO_FIFOSIZE_MASK) - 1);

	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) &

					    UARTFIFO_FIFOSIZE_MASK);



	spin_lock_irqsave(&sport->port.lock, flags);

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