Laszlo Ersek 31ae446b1a MdeModulePkg: TerminalDxe: select the UART's default receive FIFO depth ... The Serial IO protocol instances provided by SerialDxe and consumed by TerminalDxe come with a Mode.ReceiveFifoDepth=1 default setting, as required by UEFI 2.5. Although TerminalDxe calls EFI_SERIAL_IO_PROTOCOL.SetAttributes() in the TerminalDriverBindingStart() and TerminalConInTimerHandler() functions, it only does so to change the Mode.Timeout member. Other members of Mode, including Mode.ReceiveFifoDepth, are preserved. On some platforms this causes the UART that underlies TerminalDxe not to have enough room for bursts of scan codes, which translates to broken parsing of escape sequences, e.g. cursor movement keys. According to the UEFI spec, passing ReceiveFifoDepth=0 to EFI_SERIAL_IO_PROTOCOL.SetAttributes() "will use the device's default FIFO depth". While TerminalDxe could try to configure a receive FIFO depth that matches the longest escape sequence it wishes to parse, in practice the device-specific default FIFO depth -- which may well differ from the spec-mandated SerialIo->Mode.ReceiveFifoDepth=1 default -- seems to work. Hence let's just set that. This issue was exposed by SVN r18971 / git commit 921e987b2b ("ArmPlatformPkg: Use SerialDxe in MdeModulePkg instead of EmbeddedPkg"). In that conversion, MdeModulePkg's SerialDxe started to initialize Mode.ReceiveFifoDepth to 1 (in conformance with the spec), unlike the prior, non-conformant initialization to 0 in EmbeddedPkg's SerialDxe. Since TerminalDxe would never change ReceiveFifoDepth from the new default value 1, and the ArmPlatformPkg/Drivers/PL011Uart library instance, underlying SerialDxe through SerialPortLib, would obey it too, they would collectively effect a receive queue depth of 1, rather than the default 16 or 32. This broke cursor keys on the ARM FVP and Juno platforms. It is the client of EFI_SERIAL_IO_PROTOCOL that is responsible for modifying the attributes, if the defaults are not appropriate, hence this patch modifies TerminalDxe. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ryan Harkin <ryan.harkin@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Star Zeng <star.zeng@intel.com> Reported-by: Ryan Harkin <ryan.harkin@linaro.org> Reference: http://thread.gmane.org/gmane.comp.bios.edk2.devel/4779/focus=6553 Reference: http://thread.gmane.org/gmane.comp.bios.edk2.devel/6594 Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Ryan Harkin <ryan.harkin@linaro.org> Reviewed-by: Star Zeng <star.zeng@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19701 6f19259b-4bc3-4df7-8a09-765794883524		2016-01-21 00:29:12 +00:00
..
ConPlatformDxe	MdeModulePkg: Convert all .uni files to utf-8	2015-12-15 04:56:23 +00:00
ConSplitterDxe	MdeModulePkg: Convert all .uni files to utf-8	2015-12-15 04:56:23 +00:00
GraphicsConsoleDxe	MdeModulePkg: Fix GraphicsConsole driver resolution out of sync issue	2016-01-11 02:29:09 +00:00
TerminalDxe	MdeModulePkg: TerminalDxe: select the UART's default receive FIFO depth	2016-01-21 00:29:12 +00:00