korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-04 04:44:37 +08:00
Code Issues Packages Projects Releases Wiki Activity

tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A

Browse Source 
LS1028A is using DMA with LPUART. Having RX watermark set to 1, means
DMA transactions are started only after receiving the second character.

On other platforms with newer LPUART IP, Receiver Idle Empty function
initiates the DMA request after the receiver is idling for 4 characters.
But this feature is missing on LS1028A, which is causing a 1-character
delay in the RX direction on this platform.

Set RX watermark to 0 to initiate RX DMA after each character.

Link: https://lore.kernel.org/linux-serial/20230607103459.1222426-1-robert.hodaszi@digi.com/
Fixes: 9ad9df8447 ("tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case")
Cc: stable <stable@kernel.org>
Signed-off-by: Robert Hodaszi <robert.hodaszi@digi.com>
Message-ID: <20230609121334.1878626-1-robert.hodaszi@digi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Robert Hodaszi 2023-06-09 14:13:34 +02:00 committed by Greg Kroah-Hartman
parent 306320034e
commit a82c3df955
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/tty/serial/fsl_lpuart.c
View File

@ -310,7 +310,7 @@ static const struct lpuart_soc_data ls1021a_data = {
static const struct lpuart_soc_data ls1028a_data = {
.devtype = LS1028A_LPUART,
.iotype = UPIO_MEM32,
.rx_watermark = 1,
.rx_watermark = 0,
};
static struct lpuart_soc_data imx7ulp_data = {