From 46b940ddf837aa118bd514fa35e7ca6e7a5339a3 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Thu, 12 Apr 2018 14:41:43 -0700 Subject: serial/lpuart: Do not enable UART FIFO Using FIFO in LPUART results in subtle serial input draining issues which are quite difficult to reproduce and troubleshoot. Since the change offered only moderate performance gain revert the code to operate in no-FIFO mode to avoid FIFO-related problems alltogether. Signed-off-by: Andrey Smirnov Signed-off-by: Sascha Hauer --- include/serial/lpuart.h | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'include') diff --git a/include/serial/lpuart.h b/include/serial/lpuart.h index 917f644a59..a920291dec 100644 --- a/include/serial/lpuart.h +++ b/include/serial/lpuart.h @@ -238,22 +238,17 @@ static inline void lpuart_setbrg(void __iomem *base, writeb(bfra, base + UARTCR4); } -static inline void lpuart_setup_with_fifo(void __iomem *base, - unsigned int refclock, - unsigned int twfifo) +static inline void lpuart_setup(void __iomem *base, + unsigned int refclock) { /* Disable UART */ writeb(0, base + UARTCR2); writeb(0, base + UARTMODEM); writeb(0, base + UARTCR1); - if (twfifo) { - writeb(UARTPFIFO_TXFE | UARTPFIFO_RXFE, base + UARTPFIFO); - writeb((u8)twfifo, base + UARTTWFIFO); - } else { - writeb(0, base + UARTPFIFO); - writeb(0, base + UARTTWFIFO); - } + writeb(0, base + UARTPFIFO); + writeb(0, base + UARTTWFIFO); + writeb(1, base + UARTRWFIFO); writeb(UARTCFIFO_RXFLUSH | UARTCFIFO_TXFLUSH, base + UARTCFIFO); @@ -262,12 +257,6 @@ static inline void lpuart_setup_with_fifo(void __iomem *base, writeb(UARTCR2_TE | UARTCR2_RE, base + UARTCR2); } -static inline void lpuart_setup(void __iomem *base, - unsigned int refclock) -{ - lpuart_setup_with_fifo(base, refclock, 0x00); -} - static inline void lpuart_putc(void __iomem *base, int c) { if (!(readb(base + UARTCR2) & UARTCR2_TE)) -- cgit v1.2.3