Re: [PATCH] serial: 8250_dw: Prefer SRBR in bogus RX timeout workaround if available

[Andy Shevchenko]

On Mon, Jun 29, 2026 at 03:55:10PM +0800, Yicong Yang wrote:
> The DW uart could get into the cases where a bogus RX timeout
> interrupt is asserted but no available data. This could be
> workaround by doing a bogus read.
> 
> Currently the driver's using the standard RBR (receive buffer
> register) for this bogus read. However the reading of RBR
> in this case is allowed to raise a hardware error if vendor
> choose to implement in this way (our platform). It's also
> allowed to do the bogus read using SRBR (shadow RBR) for
> workaround which won't raise the hardware error. So change
> to use the SRBR to workaround the issue if it's available.

...

>  /* Offsets for the DesignWare specific registers */
> +#define DW_UART_SRBR_0	0x0c /* Shadow Receive Buffer Register */

Is this a name per DesignWare databook for UART? I mean that _0 part.

-- 
With Best Regards,
Andy Shevchenko