From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 CF2CBA59; Mon, 30 Dec 2024 11:00:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735556434; cv=none; b=CQzfBK7TyabeFQExujdK3Lb66PPUq+SBPfJrfnkKZgdfo+RhODEFNCf1v3l/ssgUrd4Oy54voe/6+ikycE4phbTLOg0XdGActO6tQ7j8Zg0PaS6zR8sxpvMaZQqAPPV67Badr/Nep6kJNWxdwCfSWtLeL4cp0TGsDrIkGERIjuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735556434; c=relaxed/simple; bh=PTsd3+QfpL+V6nSRQ63aEUuuY/516r5Yt375X+t+AmI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=HnR0VQtTk1PbKFMwGoDleHUpITNgpSw0EsTQcBjHQ3mg6vRyJiu5x0saZlzI27KlGPVmo1gPYB2U0mTFkI7lijMg7b9LT0JhFIL5+p6Jpb68+ko/aYc5CV6N3rShe8FF0gk25LgUH+M0ueMYAi8GLNMiBKpbH5KELLljsRp61+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=KgCJarP+; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=TAY3L6ai; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="KgCJarP+"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="TAY3L6ai" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1735556430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vm1NgCVjgslKq+GaJUj/gh/Sm2mhWSvo2Psz3mBxd7o=; b=KgCJarP+wCqCM94xpTM71A4ayqZ0KzEBdNLtVVoJ7jym+nWVH6lQYMVj3Ni2frYtpQay+m fjrLasdQvlOn88KoC1LCLQOqfB6/yTlGWRcbQ4XOwVuK5l3DuIz3Dv5aUungpyrFpC7h8z 5D/FP3DukdSMLJocZ8uGlPPB53Fb2RO5ytJR8oImNNoIkwlcU4Z6l9aATFKcz7C70tfMhX hCfOCCe4PXtXYqjvqGUTrb0//I5dwubNmCiQMpXGA+D1QpGQ2lMl8uApA4iPZfbXXFTxvs Rg7SYqsfOGuuoUVOOmfkht0Nu5OUj7p40fpudBRZu1m0ryJm1ii5MOhQgkaWTQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1735556430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vm1NgCVjgslKq+GaJUj/gh/Sm2mhWSvo2Psz3mBxd7o=; b=TAY3L6ai3+8KkjlmA6nrxrBsBNF5OurnSwfmxdqHg5/M4bKoZA05v3sfSUzugF00ELa8Hw 3xgj456KyrtcIMDA== To: Andy Shevchenko Cc: Greg Kroah-Hartman , Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , Esben Haabendal , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Rengarajan S , Niklas Schnelle , Serge Semin , Wander Lairson Costa , Florian Fainelli , Ray Jui , Scott Branden , Broadcom internal kernel review list , Sunil V L , Matt Turner , Stefan Wahren , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Kevin Hilman , Markus Schneider-Pargmann , Udit Kumar , Griffin Kroah-Hartman , linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Tony Lindgren Subject: Re: [PATCH tty-next v4 0/6] convert 8250 to nbcon In-Reply-To: References: <20241227224523.28131-1-john.ogness@linutronix.de> Date: Mon, 30 Dec 2024 12:06:29 +0106 Message-ID: <841pxpqvua.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2024-12-29, Andy Shevchenko wrote: > On Fri, Dec 27, 2024 at 11:51:16PM +0106, John Ogness wrote: >> This is v4 of a series to convert the 8250 driver to an NBCON >> console, providing both threaded and atomic printing >> implementations. v3 of this series is here [0]. Additional >> background information about NBCON consoles in general is >> available in the cover letter of v2 [1]. > > Just to be sure I understand the side effect of this series, i.e. > the > > https://elixir.bootlin.com/linux/v6.13-rc3/source/drivers/tty/serial/8250/8250_port.c#L44 > https://elixir.bootlin.com/linux/v6.13-rc3/source/drivers/tty/serial/8250/8250_pci.c#L9 > > are not needed anymore (the first one can be replaced to something like > dev_dbg() or analogue)? Correct. With NBCON console drivers it is safe to call printk() while holding the port lock for non-console-printing purposes because: 1. printing via ->write_atomic() does not use the port lock and 2. printing via ->write_thread() is performed in a separate dedicated printing kthread that can safely spin on the port lock John