Hi Stefan, On Wed, Aug 16, 2017 at 11:43 PM, Stefan Roese <s...@denx.de> wrote: > Hi Bin, > > On 16.08.2017 17:37, Stefan Roese wrote: >> >> To support more input characters (longer stings pasted into the U-Boot >> prompt) without dropping, lets selects the recently added UART RX >> buffer for these boards. >> >> Signed-off-by: Stefan Roese <s...@denx.de> >> Cc: Simon Glass <s...@chromium.org> >> Cc: Bin Meng <bmeng...@gmail.com> >> --- >> board/congatec/conga-qeval20-qa3-e3845/Kconfig | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/board/congatec/conga-qeval20-qa3-e3845/Kconfig >> b/board/congatec/conga-qeval20-qa3-e3845/Kconfig >> index e1fae737ac..9e44413c2c 100644 >> --- a/board/congatec/conga-qeval20-qa3-e3845/Kconfig >> +++ b/board/congatec/conga-qeval20-qa3-e3845/Kconfig >> @@ -25,6 +25,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy >> select SPI_FLASH_STMICRO >> imply SPI_FLASH_SPANSION >> imply SPI_FLASH_WINBOND >> + select SERIAL_RX_BUFFER > > > It might be better to select (or imply) this Kconfig option for x86 in > general, once this support is available in mainline. > > What do you think?
When I tested the patch on the QEMU, I got interesting results: Without the patch, QEMU's ns16550 does not lose any character or out of order when I paste a really long strings to the U-Boot console (it seems that U-Boot's maximum length for a command line is 256, so the 256 bytes are all there). After applying the patch, I got something interesting: The long strings I was using for testing was: "As Bin Meng has tested and pointed out, we don't need the RX interrupt for the RX buffer support at all. Just reading all available characters into a buffer is sufficient to solve the problem with the dropped characters upon long lines pasted into the U-Boot prompt. Since this RX buffer support can be implemented in a generic way, without any device specifica (e.g. for the ns16550), I'll post a new patch with a new serial RX buffer support for DM, which all DM based serial drivers can use. Pasting longer lines into the U-Boot console prompt sometimes leads to characters missing. One problem here is the small 16-byte FIFO of the legacy NS16550 UART, e.g. on x86 platforms. This patch now introduces a Kconfig option to enable RX buffer support for all DM based serial drivers. With this option enabled, I was able paste really long lines into the U-Boot console, without any characters missing." I just got the following strings on the console: => serial drivers. With this option enabled, I was able paste really long lines into the U-Boot console, without any characters missing. Unknown command 'serial' - try 'help' => serial drivers. With this option enabled, I was able paste really long lines into the U-Boot console, without any characters missing. Unknown command 'serial' - try 'help' All previous characters before this string are completely lost. If we want to turn this option for all x86, I think this should be fixed. Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot