From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E94AC2D0A3 for ; Mon, 26 Oct 2020 12:48:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A9D42242A for ; Mon, 26 Oct 2020 12:48:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="St/QH5Dz"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="3MMHazYD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1775424AbgJZMr5 (ORCPT ); Mon, 26 Oct 2020 08:47:57 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:39740 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1775420AbgJZMr5 (ORCPT ); Mon, 26 Oct 2020 08:47:57 -0400 Date: Mon, 26 Oct 2020 13:47:53 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603716475; 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=ledzMrALzrU/tZDU6tXmPvSq99Gfn9oi9npD1C9N7Fc=; b=St/QH5DzyWhWvhjmBWNHvcbECoE4GLaWZUK+/Co4vO3wtZ/47iDdWIm/ELt9g2EnwOIj2V qpp/7+eRu0mZR0xYlLzfkG41Pn3F5YtOR+vtuWo8tvTz/5XRAPBBMqYtpQPFjcE1FTLSMX KPnbHWnH5/aPRT9az/fIir1xZvme/oYdwdli2+62/fvCUhdh91P0W7VXgP2N8vc+5/1lu4 TyGkDJAClo5nJYZxtlrbpb/qe9aiUKSNfIi0GpdJblUWgu2kl1vN4Iw5A03Ley5rp3unHF iR9JjlSdjAumCyxHG8ddwk66Q6ZjTlGkEA7z/TFpasbrAbb5PL9ZTLIglNe1QQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603716475; 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=ledzMrALzrU/tZDU6tXmPvSq99Gfn9oi9npD1C9N7Fc=; b=3MMHazYDyT4OGKc5DsTSvyKX8/E47CLzEwIKWCPFKIt+B1VDy97ihOE78f8GwHl5Q+I1IS 0lFvGhj/pHwKbrDw== From: Sebastian Andrzej Siewior To: Johan Hovold Cc: Thomas Gleixner , LKML , Peter Zijlstra , "Ahmed S. Darwish" , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Thomas Winischhofer , Mathias Nyman , Valentina Manea , Shuah Khan , Alan Stern , linux-omap@vger.kernel.org, Kukjin Kim , Krzysztof Kozlowski , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Felipe Balbi , Duncan Sands Subject: Re: [patch V2 02/13] USB: serial: keyspan_pda: Replace in_interrupt() usage Message-ID: <20201026124753.btmdh3iwbwnff5dg@linutronix.de> References: <20201019100629.419020859@linutronix.de> <20201019101109.753597069@linutronix.de> <20201025165647.GR26280@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201025165647.GR26280@localhost> Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On 2020-10-25 17:56:47 [+0100], Johan Hovold wrote: > There's a ton of issues with this driver, but this is arguably making > things worse. A line discipline may call write() from just about any > context so we cannot rely on tty being non-NULL here (e.g. PPP). I wasn't aware of that. I've been looking at the callers each time a `tty' was passed it looked like a preemptible context (due to mutex / GFP_KERNEL) and so on. > > Johan Sebastian