Re: [PATCH v4 00/14] serial: 8250: add Moxa MUEx50 PCIe board support

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jul 30, 2026 at 08:05:45AM +0200, Jiri Slaby wrote:
> On 29. 07. 26, 8:05, Crescent Hsieh wrote:
> > This series consolidates Moxa PCIe multiport serial board support under a
> > dedicated 8250_mxpcie driver and adds MUEx50 UART support needed by these
> > boards.
> > 
> > The first part splits the existing Moxa PCIe board handling out of
> > 8250_pci into a separate driver while preserving the existing probe flow
> > and device IDs. The series then introduces the MUEx50 UART port type and
> > enables the board-specific UART setup, including enhanced mode and FIFO
> > trigger programming.
> > 
> > The driver adds hardware-assisted flow control support for MUEx50 UARTs,
> > including automatic RTS/CTS handling and XON/XOFF offload. It also adds a
> > custom IRQ path and uses the MUEx50 memory-mapped FIFO windows to improve
> > RX and TX data movement.
> > 
> > Later patches add serial interface mode switching, RS485 break handling,
> > and per-port private state for MUEx50-specific configuration. The driver
> > supports switching the serial interface mode through the RS485
> > configuration path, covering RS232, RS422, and RS485 modes supported by
> > the boards.
> > 
> > The final part extends 8250 core callbacks where needed so low-level
> > drivers can override break control and rx_trig_bytes handling. The
> > 8250_mxpcie driver uses these hooks to implement RS485 break handling via
> > MUEx50 features and to expose the MUEx50 programmable RX trigger level
> > through the generic rx_trig_bytes sysfs interface.
> > 
> > ---
> > Changes in v4:
> 
> This looks very well from my POV, except the two nits. Thanks for this.
> 
> Let's see what others say ;).

Looks sane to me, polish up those 2 things and I think it's ready to go!