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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C6D2C433F5 for ; Tue, 26 Oct 2021 06:49:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52AFA610A0 for ; Tue, 26 Oct 2021 06:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234198AbhJZGwK (ORCPT ); Tue, 26 Oct 2021 02:52:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:57996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232907AbhJZGwJ (ORCPT ); Tue, 26 Oct 2021 02:52:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 53639603E5; Tue, 26 Oct 2021 06:49:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635230985; bh=6f1WgNicKHo46BidqiQs8hGNGw8fYd/fygv8pn1WdIU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JE2IgUzDQ9FhimLGtgYmJx7gfk7AbNK8FCvuy+1XpMpsYY3/phH8JvRkEQ5yDvHKL Fd8XM/W5vYHq+hiyfbvecJa62VcdGpzx0iI7SZIwoQM75oQELC2TAaF5xNQQswVtY3 5+mM1WbvM6FhxDYvZtnIecqDd7+r/R6ui7u/9GjQ= Date: Tue, 26 Oct 2021 08:49:43 +0200 From: Greg KH To: Xianting Tian Cc: Jiri Slaby , amit@kernel.org, arnd@arndb.de, osandov@fb.com, shile.zhang@linux.alibaba.com, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v11 2/3] tty: hvc: pass DMA capable memory to put_chars() Message-ID: References: <20211015024658.1353987-1-xianting.tian@linux.alibaba.com> <20211015024658.1353987-3-xianting.tian@linux.alibaba.com> <208f7a41-a9fa-630c-cb44-c37c503f3a72@kernel.org> <8f78c1b8-c736-748d-d08b-3d6121eb5af8@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8f78c1b8-c736-748d-d08b-3d6121eb5af8@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 26, 2021 at 02:11:51PM +0800, Xianting Tian wrote: > > 在 2021/10/26 下午2:10, Greg KH 写道: > > On Tue, Oct 26, 2021 at 02:02:21PM +0800, Xianting Tian wrote: > > > 在 2021/10/26 下午1:10, Jiri Slaby 写道: > > > > On 15. 10. 21, 4:46, Xianting Tian wrote: > > > > > @@ -151,9 +142,11 @@ static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = > > > > >   static void hvc_console_print(struct console *co, const char *b, > > > > >                     unsigned count) > > > > >   { > > > > > -    char c[N_OUTBUF] __ALIGNED__; > > > > > +    char *c; > > > > >       unsigned i = 0, n = 0; > > > > >       int r, donecr = 0, index = co->index; > > > > > +    unsigned long flags; > > > > > +    struct hvc_struct *hp; > > > > >         /* Console access attempt outside of acceptable console > > > > > range. */ > > > > >       if (index >= MAX_NR_HVC_CONSOLES) > > > > > @@ -163,6 +156,13 @@ static void hvc_console_print(struct console > > > > > *co, const char *b, > > > > >       if (vtermnos[index] == -1) > > > > >           return; > > > > >   +    hp = cons_hvcs[index]; > > > > > +    if (!hp) > > > > > +        return; > > > > You effectively make the console unusable until someone calls > > > > hvc_alloc() for this device, correct? This doesn't look right. Neither > > > > you describe this change of behaviour in the commit log. > > > I mentioned such info in the commit log: > > > 'Introduce another array(cons_hvcs[]) for hvc pointers next to the > > > cons_ops[] and vtermnos[] arrays. With the array, we can easily find > > > hvc's cons_outbuf and its lock.' > > > > > > After you pointed it out, I just found what you said make sense, I checked the code hvc_console_print() can support print before hvc_alloc() is called when someone use hvc_instantiate() for an early console discovery method. > > > I send a patch to fix the issue? or these serial pathches reverted fisrtly then I resend new version patches? thanks > > Let me revert these now and you can send an updated version. > OK, thanks. I have now reverted patches 2/3 and 3/3 in this series from my tree. The first patch was just fine. thanks, greg k-h