Reviewed-by: Zhichao Gao <zhichao....@intel.com> Thanks, Zhichao
> -----Original Message----- > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ashish > Singhal > Sent: Tuesday, January 28, 2020 1:53 AM > To: devel@edk2.groups.io; Wang, Jian J <jian.j.w...@intel.com>; Wu, Hao A > <hao.a...@intel.com>; Gao, Zhichao <zhichao....@intel.com>; Ni, Ray > <ray...@intel.com> > Cc: Ashish Singhal <ashishsin...@nvidia.com> > Subject: [edk2-devel] [PATCH] MdeModulePkg/BaseSerialPortLib16550: Fix > Serial Port Ready > > Before writing data to FIFO, wait for the serial port to be ready, to make > sure > both the transmit FIFO and shift register empty. Code comment was saying the > right thing but code was missing a check. > > Signed-off-by: Ashish Singhal <ashishsin...@nvidia.com> > --- > .../Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git > a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c > b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c > index bbae379887..9cb50dd80d 100644 > --- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c > +++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550 > +++ .c > @@ -646,7 +646,7 @@ SerialPortWrite ( > // Wait for the serial port to be ready, to make sure both the transmit > FIFO > // and shift register empty. > // > - while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & > B_UART_LSR_TEMT) == 0); > + while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & > + (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | > + B_UART_LSR_TXRDY)); > > // > // Fill then entire Tx FIFO > -- > 2.17.1 > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#53802): https://edk2.groups.io/g/devel/message/53802 Mute This Topic: https://groups.io/mt/70161119/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
