Re: [PATCH v2] tty: make pl011 serial port driver support 485 mode
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-01-07 15:14:41
Also in:
lkml
On Thu, Jan 07, 2021 at 02:16:41PM +0800, zhangqiumiao1@huawei.com wrote:
From: Qiumiao Zhang <redacted> make pl011 serial port support 485 mode full duplex communication Signed-off-by: Qiumiao Zhang <redacted> --- Changes in v2: - Fix two compilation errors
What changed from the version you sent yesterday with this same subject line?
quoted hunk
drivers/tty/serial/amba-pl011.c | 38 +++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index c255476cce28..f6a7fe61e699 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c@@ -44,6 +44,7 @@ #include "amba-pl011.h" +#define ISEMPTY 1 #define UART_NR 14 #define SERIAL_AMBA_MAJOR 204@@ -1284,14 +1285,33 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) #define pl011_dma_flush_buffer NULL #endif +static unsigned int pl011_tx_empty(struct uart_port *port); + static void pl011_stop_tx(struct uart_port *port) { + unsigned int cr; + unsigned int result;
But below the uap definition please, like kernel style normally is.
quoted hunk
struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); uap->im &= ~UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); pl011_dma_tx_stop(uap); + if (port->rs485.flags & SER_RS485_ENABLED) { + while(1) { + result = pl011_tx_empty(port); + if (ISEMPTY == result) { + break; + }
It's not ok to busy loop forever, sorry.
quoted hunk
+ } + cr = pl011_read(uap, REG_CR); + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) { + cr |= UART011_CR_RTS; + } else { + cr &= ~UART011_CR_RTS; + }
Did you run checkpatch on this code? Please fix up. thanks, greg k-h