From 719a347c5df53a1dca6f80e06a285424228436e1 Mon Sep 17 00:00:00 2001 From: Evan Lloyd Date: Wed, 21 Sep 2016 21:33:13 +0100 Subject: [PATCH] ArmPlatformPkg: Fix PL011 FIFO size test This change updates PL011UartInitializePort to compare ReceiveFifoDepth with the correct hardware FIFO size instead of the constant 32 used previously. This corrects a minor bug where a request for a fifo size > 15 and < 32 would not have been honoured on a system with a 16 byte FIFO. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Sami Mujawar Signed-off-by: Evan Lloyd Reviewed-by: Leif Lindholm --- ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c index 3748972acb..b3ea138bf6 100644 --- a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c +++ b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c @@ -79,17 +79,18 @@ PL011UartInitializePort ( UINT32 Divisor; UINT32 Integer; UINT32 Fractional; + UINT32 HardwareFifoDepth; + HardwareFifoDepth = (PL011_UARTPID2_VER (MmioRead32 (UartBase + UARTPID2)) \ + > PL011_VER_R1P4) \ + ? 32 : 16 ; // The PL011 supports a buffer of 1, 16 or 32 chars. Therefore we can accept // 1 char buffer as the minimum FIFO size. Because everything can be rounded // down, there is no maximum FIFO size. - if ((*ReceiveFifoDepth == 0) || (*ReceiveFifoDepth >= 32)) { + if ((*ReceiveFifoDepth == 0) || (*ReceiveFifoDepth >= HardwareFifoDepth)) { // Enable FIFO LineControl = PL011_UARTLCR_H_FEN; - if (PL011_UARTPID2_VER (MmioRead32 (UartBase + UARTPID2)) > PL011_VER_R1P4) - *ReceiveFifoDepth = 32; - else - *ReceiveFifoDepth = 16; + *ReceiveFifoDepth = HardwareFifoDepth; } else { // Disable FIFO LineControl = 0;