ok
On Mon, Jun 28, 2021 at 7:04 AM Kinsey Moore <kinsey.mo...@oarcorp.com> wrote:
>
> The existing fix for the ZynqMP UART hardware bug only caught the vast
> majority of instances where it could occur. To fully fix the data
> corruption, this fix must be applied after every baud rate change. This
> makes the logic reset and kick apply in any locations where the baud
> rate could be changed.
> ---
> bsps/aarch64/xilinx-zynqmp/console/console.c | 5 -----
> bsps/shared/dev/serial/zynq-uart-polled.c | 6 ++++++
> bsps/shared/dev/serial/zynq-uart.c | 8 ++++++++
> 3 files changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/bsps/aarch64/xilinx-zynqmp/console/console.c
> b/bsps/aarch64/xilinx-zynqmp/console/console.c
> index 9886a117dc..d1948f1a0c 100644
> --- a/bsps/aarch64/xilinx-zynqmp/console/console.c
> +++ b/bsps/aarch64/xilinx-zynqmp/console/console.c
> @@ -113,11 +113,6 @@ static void zynqmp_debug_console_early_init(char c)
>
> zynq_uart_initialize(base);
> BSP_output_char = zynqmp_debug_console_out;
> - /*
> - * Some ZynqMP UARTs have a hardware bug that causes TX/RX logic restarts
> to
> - * require a kick after baud rate registers are initialized.
> - */
> - zynqmp_debug_console_out(0);
> zynqmp_debug_console_out(c);
> }
>
> diff --git a/bsps/shared/dev/serial/zynq-uart-polled.c
> b/bsps/shared/dev/serial/zynq-uart-polled.c
> index 74e7255ec2..95c51dea11 100644
> --- a/bsps/shared/dev/serial/zynq-uart-polled.c
> +++ b/bsps/shared/dev/serial/zynq-uart-polled.c
> @@ -144,6 +144,12 @@ void zynq_uart_initialize(rtems_termios_device_context
> *base)
> regs->control = ZYNQ_UART_CONTROL_RXEN
> | ZYNQ_UART_CONTROL_TXEN
> | ZYNQ_UART_CONTROL_RSTTO;
> +
> + /*
> + * Some ZynqMP UARTs have a hardware bug that causes TX/RX logic restarts
> to
> + * require a kick after baud rate registers are initialized.
> + */
> + zynq_uart_write_polled(base, 0);
> }
>
> int zynq_uart_read_polled(rtems_termios_device_context *base)
> diff --git a/bsps/shared/dev/serial/zynq-uart.c
> b/bsps/shared/dev/serial/zynq-uart.c
> index cd0d0e7584..8503e31d49 100644
> --- a/bsps/shared/dev/serial/zynq-uart.c
> +++ b/bsps/shared/dev/serial/zynq-uart.c
> @@ -214,9 +214,17 @@ static bool zynq_uart_set_attributes(
> if (baud > 0) {
> regs->baud_rate_gen = ZYNQ_UART_BAUD_RATE_GEN_CD(brgr);
> regs->baud_rate_div = ZYNQ_UART_BAUD_RATE_DIV_BDIV(bauddiv);
> + regs->control |= ZYNQ_UART_CONTROL_RXRES
> + | ZYNQ_UART_CONTROL_TXRES;
> }
> regs->control |= ZYNQ_UART_CONTROL_RXEN | ZYNQ_UART_CONTROL_TXEN;
>
> + /*
> + * Some ZynqMP UARTs have a hardware bug that causes TX/RX logic restarts
> to
> + * require a kick after baud rate registers are initialized.
> + */
> + zynq_uart_write_polled(context, 0);
> +
> return true;
> }
>
> --
> 2.20.1
>
> _______________________________________________
> devel mailing list
> devel@rtems.org
> http://lists.rtems.org/mailman/listinfo/devel
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