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serial: xuartps: fix typo in cdns_uart_startup 

The bit mask changes in commit 6e14f7c1f2 ("tty: xuartps: Improve
startup function") doesn't do what the commit message advertises. The
original behaviour was clearing the RX_DIS bit, but due to missing ~,
that bit is now the only bit kept.

Currently, the regression is harmless, because the previous write to the
control register sets it to TXRST | RXRST. Thus the RX_DIS bit is
previously cleared. The *RST bits are cleared by the hardware, so this
commit does not currently change behaviour, but makes future changes
less risky.

Link: https://www.spinics.net/lists/linux-serial/msg23157.html
Signed-off-by: Helmut Grohne <h.grohne@intenta.de>
Fixes: 6e14f7c1f2 ("tty: xuartps: Improve startup function")
Reviewed-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Helmut Grohne 2018-06-04 12:22:05 +02:00 committed by Greg Kroah-Hartman
parent 85c634e919
commit 68d12bb267
1 changed files with 1 additions and 1 deletions
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2
drivers/tty/serial/xilinx_uartps.c
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@ -829,7 +829,7 @@ static int cdns_uart_startup(struct uart_port *port)
* the receiver.
*/
status = readl(port->membase + CDNS_UART_CR);
status &= CDNS_UART_CR_RX_DIS;
status &= ~CDNS_UART_CR_RX_DIS;
status |= CDNS_UART_CR_RX_EN;
writel(status, port->membase + CDNS_UART_CR);