From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8505338642C; Tue, 13 Oct 2026 05:49:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791870593; cv=none; b=PoJBTqGH1tnwN7rdY7ylhhv7ABedgFmHY80gUG4FVcE2JfZm1FsjNm/uaIKcQIAoUDnX5hQbU1WHdxJgxt7CMWlhikCKNu1gw/R3i7FpCyBJnQLwlaKXxR93Wli8tRaCrNev+dHGF2sFC2GdwS/BPf0MKW8Xj6qmrON44a2y4R4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791870593; c=relaxed/simple; bh=wuRY5p+5BrzZUH6eJDHauD3cZJW0aNAJikIfR7tCCd8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RrkvXfyME6Q1vzejdYD7CqqovtK1MeM5FZm07NRXSMv7HahhHWrHg5ibNxtyjOPM+BUEvcFNhGxq2HSbstkx1r6PoI+Rw3MZCKpCcNbOSzgRVTSykszKe41qwilM25QLLnYPIkCKgZDJU0J63Flq/WEq5si/fu7XwMgLytoTeVY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kOM7OoZN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kOM7OoZN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A9FE1F000FF; Tue, 13 Oct 2026 05:49:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791870592; bh=11l6/oERXgMW/KfZBlSq4z+sWH/hdPWsPSIDxfpMm/I=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kOM7OoZNkeQoeZUBmGA9S1uzERXrskTIHg0Dlh4HAYCrI3BAKKGjCcjiWIl1RCJyC BZiJOvFz0c8t5bh6t6eUnpw/VLARFyplhuj51o5LaxqqWt/oWzTXah++nRmhWS6Cs9 Jyc9GHqTJ7d+JBOTWytsy+x+HvT3gNTq4Zyr9fLa3RpCIqYsrwI5BjYuH0ULwuBDiL agitrCz3TUWqpmVJiLzg9wjtqUJnjgA84Hdd8vo6Jkmn5Hfo6S/Vd2vVjIaFcRa4UJ bCEc3W0/65OPvP76z0CcDL4uR/WI0ELdUaxL9yncxwDv+GqCoccRPiDPSdZdAS4LN/ Bsw1R7pYzLzgg== Message-ID: <558332ed-b93e-4f0d-abb0-942ca63b0cd6@kernel.org> Date: Tue, 13 Oct 2026 07:49:47 +0200 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 10/11] tty: Add NVIDIA LSTP UART driver To: Adrian Ambrozewicz , Greg Kroah-Hartman Cc: Donald Shannon , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, llvm@lists.linux.dev, =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , Johan Hovold , Oliver Neukum References: <20261012-lstp-usb-adapter-v1-0-aambrozewicz@nvidia.com> <20261012-lstp-usb-adapter-v1-10-aambrozewicz@nvidia.com> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 12. 10. 26, 19:36, Adrian Ambrozewicz wrote: > --- /dev/null > +++ b/drivers/tty/lstp_tty.c > @@ -0,0 +1,829 @@ ... > +/* clang-format off */ > +static speed_t lstp_baud_to_speed(u32 baud) Maybe implement this in drivers/tty/tty_baudrate.c on the top of baud_table + baud_bits? > +{ > + static const struct { > + u32 baud; > + speed_t speed; > + } map[] = { > + { 50, B50 }, { 75, B75 }, { 110, B110 }, > + { 134, B134 }, { 150, B150 }, { 200, B200 }, > + { 300, B300 }, { 600, B600 }, { 1200, B1200 }, > + { 1800, B1800 }, { 2400, B2400 }, { 4800, B4800 }, > + { 9600, B9600 }, { 19200, B19200 }, { 38400, B38400 }, > + { 57600, B57600 }, { 115200, B115200 }, { 230400, B230400 }, > + { 460800, B460800 }, { 500000, B500000 }, { 576000, B576000 }, > + { 921600, B921600 }, { 1000000, B1000000 }, { 1152000, B1152000 }, > + { 1500000, B1500000 }, { 2000000, B2000000 }, { 2500000, B2500000 }, > + { 3000000, B3000000 }, { 3500000, B3500000 }, { 4000000, B4000000 }, > + }; > + > + for (size_t i = 0; i < ARRAY_SIZE(map); i++) > + if (map[i].baud == baud) > + return map[i].speed; > + > + return B0; > +} ... > +static int lstp_uart_start(struct lstp_channel *ch) > +{ > + struct lstp_uart_ctx *ctx = ch->priv; > + > + /* > + * Mark registered before publishing: tty_port_register_device() adds > + * the cdev and emits the uevent that sends udev straight to open(), > + * and lstp_tty_install() refuses a minor that is not marked. No node > + * exists at this index yet, so nothing can reach the map early. > + */ > + scoped_guard(mutex, &lstp_minors_lock) > + ctx->registered = true; > + > + struct device *tty_dev = > + tty_port_register_device(&ctx->port, lstp_tty_driver, ctx->minor, ch->dev); > + > + if (IS_ERR(tty_dev)) { > + dev_err(ch->dev, "%s: ch_%d: Could not register TTY (%pe)\n", __func__, ch->ch_id, > + tty_dev); > + scoped_guard(mutex, &lstp_minors_lock) > + ctx->registered = false; > + return PTR_ERR(tty_dev); > + } > + > + /* Nothing below may fail: really_probe() skips .remove() when .probe() errors. */ > + dev_info(ch->dev, "%s: ch_%d: Started as %s\n", __func__, ch->ch_id, ch->display_name); We usually print nothing in case everything went well. > + return 0; > +} ... > +static void lstp_uart_stop(struct lstp_channel *ch) > +{ > + struct lstp_uart_ctx *ctx = ch->priv; > + > + /* > + * Clear @registered before sampling @port->tty, not after: > + * tty_port_open() publishes the tty before it calls .activate(), so an > + * open can go live between a sample and a later clear and never be > + * hung up here. > + */ > + scoped_guard(mutex, &lstp_minors_lock) > + ctx->registered = false; > + > + struct tty_struct *tty = tty_port_tty_get(&ctx->port); > + > + if (tty) { > + /* > + * Synchronous: fds move to hung_up_tty_fops and lstp_port_shutdown() > + * cancels write_work, so no write is submitted after this returns. > + */ > + tty_vhangup(tty); > + tty_kref_put(tty); tty_port_tty_vhangup()? > + } > + > + tty_unregister_device(lstp_tty_driver, ctx->minor); > +} thanks, -- js suse labs