From: Johan Hovold <johan@kernel.org>
To: "Ji-Ze Hong (Peter Hong)" <peter_hong@fintek.com.tw>
Cc: hpeter+linux_kernel@gmail.com, gregkh@linuxfoundation.org,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
tom_tsai@fintek.com.tw, yu_chen@fintek.com.tw
Subject: Re: [PATCH V3 1/1] USB: serial: f81232: fix incomplete serial port generation
Date: Tue, 13 Jan 2026 16:04:58 +0100 [thread overview]
Message-ID: <aWZfGgQx6HXglmXX@hovoldconsulting.com> (raw)
In-Reply-To: <20251212070831.16334-1-peter_hong@fintek.com.tw>
On Fri, Dec 12, 2025 at 03:08:31PM +0800, Ji-Ze Hong (Peter Hong) wrote:
> The Fintek F81532A/534A/535/536 family relies on the
> F81534A_CTRL_CMD_ENABLE_PORT (116h) register during initialization to
> both determine serial port status and control port creation. If the
> driver experiences fast load/unload cycles, the device state may becomes
> unstable, resulting in the incomplete generation of serial ports.
>
> Performing a dummy read operation on the register prior to the initial
> write command resolves the issue. This clears the device's stale internal
> state. Subsequent write operations will correctly generate all serial
> ports.
>
> This patch also removes the retry loop in f81534a_ctrl_set_register()
> because the stale state has been fixed.
>
> Tested on: HygonDM1SLT(Hygon C86 3250 8-core Processor)
>
> Signed-off-by: Ji-Ze Hong (Peter Hong) <peter_hong@fintek.com.tw>
> ---
Next time, please remember to include a short changelog here under the
cut off line (---).
Now applied, thanks.
Johan
prev parent reply other threads:[~2026-01-13 15:05 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-12 7:08 Ji-Ze Hong (Peter Hong)
2026-01-13 15:04 ` Johan Hovold [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aWZfGgQx6HXglmXX@hovoldconsulting.com \
--to=johan@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=hpeter+linux_kernel@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=peter_hong@fintek.com.tw \
--cc=tom_tsai@fintek.com.tw \
--cc=yu_chen@fintek.com.tw \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®