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 1229A1E7C09 for ; Mon, 21 Oct 2024 12:27:48 +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=1729513670; cv=none; b=pQK2gR02t8ZzVPsPrtg4TGHdVZ+5fOB88jW8QfxIS25kgY+UCKFdtZgjjU/lNYy6e5OWzsVKdj2/gqpGO/Sqyj6CNbozu98QtQ8VEOjWcy3ilhgtls3b5102aTl1cp+jPxqudMj4mQfXvfU5YECY/OI7xGJDVpdemtsdGvPC/z4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729513670; c=relaxed/simple; bh=IGK5XyR7IlNtmOeaNTr+p/k+f61t96h/7mLGFkS+aUs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=g8eoqn+Ue+d9BiL7JmDo9Go5U+LAMHbumZB8uEwrDFEWicRka79YiY0JSK/0co2CEaYG5xGnUe5v8eR6XxGizBvf62fX6gC69acz7pC6FTOHey0pQl3drtjIkEVqdvpgFn8JvmsWx1X+AFvPK+iVRlKmXAzVc9eEnqpNjEfuDu4= 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=FTfTwZiv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=jrFA/5hQ; 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="FTfTwZiv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="jrFA/5hQ" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1729513667; 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=99jFXW/CwdyRcK8sGANnfyq1NG9lVOM4bAuwhhPMZ3Q=; b=FTfTwZivkJNNhVUSQLAGwI4zc3HGwCHeWIQA0KRcXWbxaIpgYlngv319X4Uv76M05mAzUF 22eCKrIOuqvbcI7TaLpvYlkfncXaP3jLvoqqnuQeQEySbVqszPIhZgfAT3okHPkbOJUSbK IbAUIHTGs/UFQt+u8h2Dq2WY1lQY3mFC2kashseP/IUONO/GBVhPx/44NC/XeP8TRmY+sA rPvhpqHjdwUpCecLlwkzAQsIoTbLBz4IvJZD9/MN+/ESx2TCDXQwX5cOK9K5nNKizzSr8K cB8CTiksFaTuKECBpLrjbUpPCt37kSF7zqnqDK7iVzwxrDubIe7ybOm/S5EeuA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1729513667; 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=99jFXW/CwdyRcK8sGANnfyq1NG9lVOM4bAuwhhPMZ3Q=; b=jrFA/5hQfVqm9mel2IJlzbl//WFQCYPiYzZVO8TNDBHkNTn0/XLklq6P50n5V5eh1cGQiz 7OE84fab6r5wXfBA== To: Ryo Takakura Cc: christophe.leroy@csgroup.eu, hbathini@linux.ibm.com, leobras.c@gmail.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com, mpe@ellerman.id.au, naveen@kernel.org, npiggin@gmail.com, pmladek@suse.com, ryotkkr98@gmail.com, sourabhjain@linux.ibm.com Subject: Re: [PATCH] powerpc/crash: Allow direct printing on kexec In-Reply-To: <20241021121159.331940-1-ryotkkr98@gmail.com> References: <844j56v75z.fsf@jogness.linutronix.de> <20241021121159.331940-1-ryotkkr98@gmail.com> Date: Mon, 21 Oct 2024 14:33:46 +0206 Message-ID: <847ca1fxod.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 2024-10-21, Ryo Takakura wrote: >> Rather than removing the deferring, it would be better to convert the >> console you are using to the new NBCON API. Then it would be able to >> print direct and safe during panic. (printk_deferred does not affect >> NBCON consoles.) What console driver are you using that you want to >> see the messages on? > > I was working on qemu ppc64 this time but I am usually working on > Raspberry Pi 4 (mostly for fun and study) which uses either of > bcm2835-aux-uart or amba-pl011. It would be really nice to see them > working as nbcon! > I am thinking of taking a look at [0] but If there were any other > references, I would really like to look into as well. > > [0] https://lore.kernel.org/lkml/87wn3zsz5x.fsf@jogness.linutronix.de/ The lastest version of the series is here [1]. The series is still undergoing revisions, however the changes are 8250-specific. The API for nbcon consoles is already available since 6.12-rc1. You are certainly welcome to try to convert one of those Raspi 4 drivers to the nbcon interface. I would be happy to review it. John Ogness [1] https://lore.kernel.org/lkml/20240913140538.221708-1-john.ogness@linutronix.de