From c8edb70945099fd35a0997d3f3db105efc144e13 Mon Sep 17 00:00:00 2001 From: Irene Park Date: Tue, 9 Jun 2020 13:56:31 -0400 Subject: ArmPlatformPkg/PL011UartLib: Check PID2 if FiFoDepth is zero PL011UartLib determines its FIFO depth based on the PID2 value but the register PID2 is not mandatory as per the SBSA spec. This change won't check PID2 if PcdUartDefaultReceiveFifoDepth is set to a value > 0. Signed-off-by: Irene Park Reviewed-by: Ard Biesheuvel --- ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c | 10 +++++++--- ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf | 1 + 2 files changed, 8 insertions(+), 3 deletions(-) (limited to 'ArmPlatformPkg/Library') diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c index 801990d955..f1015b1fce 100644 --- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c +++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c @@ -78,10 +78,14 @@ PL011UartInitializePort ( UINT32 Integer; UINT32 Fractional; UINT32 HardwareFifoDepth; + UINT32 UartPid2; + + HardwareFifoDepth = FixedPcdGet16 (PcdUartDefaultReceiveFifoDepth); + if (HardwareFifoDepth == 0) { + UartPid2 = MmioRead32 (UartBase + UARTPID2); + HardwareFifoDepth = (PL011_UARTPID2_VER (UartPid2) > PL011_VER_R1P4) ? 32 : 16; + } - 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. diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf index d99e89fe00..e3da507988 100644 --- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf +++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf @@ -30,6 +30,7 @@ ArmPlatformPkg/ArmPlatformPkg.dec [FixedPcd] + gEfiMdePkgTokenSpaceGuid.PcdUartDefaultReceiveFifoDepth gEfiMdeModulePkgTokenSpaceGuid.PcdSerialBaudRate gArmPlatformTokenSpaceGuid.PL011UartInteger -- cgit v1.2.3