diff options
| -rw-r--r-- | c/src/libchip/serial/ns16550-context.c | 14 | ||||
| -rw-r--r-- | c/src/libchip/serial/ns16550.h | 2 |
2 files changed, 13 insertions, 3 deletions
diff --git a/c/src/libchip/serial/ns16550-context.c b/c/src/libchip/serial/ns16550-context.c index 8901590522..3c419780ae 100644 --- a/c/src/libchip/serial/ns16550-context.c +++ b/c/src/libchip/serial/ns16550-context.c @@ -148,6 +148,7 @@ bool ns16550_probe(rtems_termios_device_context *base) /* Set the divisor latch and set the baud rate. */ ulBaudDivisor = NS16550_GetBaudDivisor(ctx, ctx->initial_baud); + ctx->baud_divisor = ulBaudDivisor; ucDataByte = SP_LINE_DLAB; (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); @@ -161,6 +162,7 @@ bool ns16550_probe(rtems_termios_device_context *base) /* Clear the divisor latch and set the character size to eight bits */ /* with one stop bit and no parity checking. */ ucDataByte = EIGHT_BITS; + ctx->line_control = ucDataByte; (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); /* Enable and reset transmit and receive FIFOs. TJA */ @@ -585,7 +587,6 @@ static bool ns16550_set_attributes( uint8_t ucLineControl; uint32_t baud_requested; ns16550_set_reg setReg; - rtems_interrupt_lock_context lock_context; pNS16550 = ctx->port; setReg = ctx->set_reg; @@ -642,7 +643,13 @@ static bool ns16550_set_attributes( * Now actually set the chip */ - rtems_termios_device_lock_acquire(base, &lock_context); + if (ulBaudDivisor != ctx->baud_divisor || ucLineControl != ctx->line_control) { + rtems_interrupt_lock_context lock_context; + + ctx->baud_divisor = ulBaudDivisor; + ctx->line_control = ucLineControl; + + rtems_termios_device_lock_acquire(base, &lock_context); /* * Set the baud rate @@ -661,7 +668,8 @@ static bool ns16550_set_attributes( */ (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucLineControl ); - rtems_termios_device_lock_release(base, &lock_context); + rtems_termios_device_lock_release(base, &lock_context); + } return true; } diff --git a/c/src/libchip/serial/ns16550.h b/c/src/libchip/serial/ns16550.h index 19ac3f1152..4f1b98bf0b 100644 --- a/c/src/libchip/serial/ns16550.h +++ b/c/src/libchip/serial/ns16550.h @@ -70,6 +70,8 @@ typedef struct { uint32_t initial_baud; bool has_fractional_divider_register; uint8_t modem_control; + uint8_t line_control; + uint32_t baud_divisor; size_t out_total; size_t out_remaining; size_t out_current; |