tty: serial: fsl_lpuart: Clear the error flags by writing 1 for lpuart32 platforms
authorSherry Sun <sherry.sun@nxp.com>
Tue, 1 Aug 2023 02:23:04 +0000 (10:23 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 23 Aug 2023 15:52:31 +0000 (17:52 +0200)
commit0693c8f134f97f8973621be76b17be8efbe17589
tree77655d8c52ec4f447389bf84c7dce894c2e1e30b
parent31311a9a4baae0ad47c85e448af21b2120344ff0
tty: serial: fsl_lpuart: Clear the error flags by writing 1 for lpuart32 platforms

commit 282069845af388b08d622ad192b831dcd0549c62 upstream.

Do not read the data register to clear the error flags for lpuart32
platforms, the additional read may cause the receive FIFO underflow
since the DMA has already read the data register.
Actually all lpuart32 platforms support write 1 to clear those error
bits, let's use this method to better clear the error flags.

Fixes: 42b68768e51b ("serial: fsl_lpuart: DMA support for 32-bit variant")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20230801022304.24251-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/fsl_lpuart.c