On Mon, Aug 21, 2023 at 11:52:51AM -0700, Justin Chen wrote:
> The 8250 BCM7271 UART is not a direct match to PORT_16550A and other
> generic ports do not match its hardware capabilities. PORT_ALTR matches
> the rx trigger levels, but its vendor configurations are not compatible.
> Unfortunately this means we need to create another port to fully capture
> the hardware capabilities of the BCM7271 UART.
>
> To alleviate some latency pressures, we default the rx trigger level to 8.
FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
...
> + [PORT_BCM7271] = {
> + .name = "Broadcom BCM7271 UART",
> + .fifo_size = 32,
> + .tx_loadsz = 32,
> + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
> + .rxtrig_bytes = {1, 8, 16, 30},
> + .flags = UART_CAP_FIFO | UART_CAP_AFE,
> + },
Strictly speaking it's better to keep this ordered according to the number, but
it's fine like this anyway.
--
With Best Regards,
Andy Shevchenko
