linux-kernel - Re: [PATCH v1 22/31] serial: 8250_mxupci: implement rx_trig_bytes callbacks and persist per-port level

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHp75VeUXNW1tN6MKp6jNebtS+Ek05yszADVr6sgME+G0jzUhw@mail.gmail.com>
Date: Mon, 1 Dec 2025 04:03:49 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Crescent Hsieh <crescentcy.hsieh@...a.com>
Cc: gregkh@...uxfoundation.org, jirislaby@...nel.org, 
	ilpo.jarvinen@...ux.intel.com, linux-kernel@...r.kernel.org, 
	linux-serial@...r.kernel.org
Subject: Re: [PATCH v1 22/31] serial: 8250_mxupci: implement rx_trig_bytes
 callbacks and persist per-port level

On Sun, Nov 30, 2025 at 12:45 PM Crescent Hsieh
<crescentcy.hsieh@...a.com> wrote:
>
> Implement device-specific RX trigger handling for the rx_trig_bytes sysfs
> attribute on MXUPCI parts by programming the vendor registers directly.
>
> Changes:
> - Introduce a per-port structure to persist the registered line and the
>   RX trigger level, so the level can be restored on startup.
> - Implement uart_port callbacks:
>     - set_rxtrig(port, bytes): program MOXA_UART_RBRTI and cache the level
>     - get_rxtrig(port):        return the cached RX trigger level
> - Use the cached RX trigger level during startup instead of a fixed
>   default, while keeping the initial default at 96 for backward
>   compatibility.
>
> With these callbacks, writes to rx_trig_bytes update the hardware-specific
> register and the selected threshold is preserved across open/close cycles.
>
> No functional change for other 8250 drivers.

Same comments applied here as per previous patch.

-- 
With Best Regards,
Andy Shevchenko