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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C871C433F5 for ; Thu, 29 Sep 2022 11:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235002AbiI2LTV (ORCPT ); Thu, 29 Sep 2022 07:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234798AbiI2LTS (ORCPT ); Thu, 29 Sep 2022 07:19:18 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78B0014AD69; Thu, 29 Sep 2022 04:19:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664450357; x=1695986357; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=Whifblvle5Uq5hTKfSa28zbbpyf+/wOvfOuC9En91aQ=; b=dWoYWeOfZPC5ztJOc26+L7kfGRRqAimIeLDvW4Sp12lEpVaxq3WqdH58 zZzqAXw8qWgNn7RbfymKngYlu5Kb//wnVxt3a/KfaHp8+C4DJu9G+fU5n fjAEUzrZtzXSltez513T2CU/O5cYfoHHZE8q3J3QZhOjN/mWL4arVJ/xe wJv8VzLMnROOpT07vgdWB3pR/vyS+W4QzoJrfDchnFiWwVvkHGHAPTYZa kB06ESLCUJqkONgkj6q/UuUmpLwyd/3qIGTUutdXDHqZCUo+8S5kVzg+f Qo48gyL7yjEB5CTHwVhE3M7sN20NTLlr98P6B8nMAHWxcRp13ZHUrTkJd g==; X-IronPort-AV: E=McAfee;i="6500,9779,10484"; a="363708788" X-IronPort-AV: E=Sophos;i="5.93,354,1654585200"; d="scan'208";a="363708788" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2022 04:19:17 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10484"; a="951091159" X-IronPort-AV: E=Sophos;i="5.93,354,1654585200"; d="scan'208";a="951091159" Received: from pramona-mobl1.ger.corp.intel.com ([10.252.60.139]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2022 04:19:10 -0700 Date: Thu, 29 Sep 2022 14:19:06 +0300 (EEST) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Sherry Sun cc: Greg Kroah-Hartman , Jiri Slaby , Lukas Wunner , linux-serial , LKML , dl-linux-imx Subject: RE: [PATCH] Revert "serial: fsl_lpuart: Reset prior to registration" In-Reply-To: Message-ID: <39c68295-947-2353-d9b-3bd654c38c7@linux.intel.com> References: <20220929085318.5268-1-sherry.sun@nxp.com> <1265873d-28f9-d39c-5cce-858dbed1e8e8@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Sep 2022, Sherry Sun wrote: > > > This reverts commit 60f361722ad2ae5ee667d0b0545d40c42f754daf. > > > > > > commit 60f361722ad2 ("serial: fsl_lpuart: Reset prior to > > > registration") causes the lpuart console cannot work any more. Since > > > the console is registered in the uart_add_one_port(), the driver > > > cannot identify the console port before call uart_add_one_port(), > > > which causes all the uart ports including the console port will be global > > reset. > > > So need to revert this patch to avoid breaking the lpuart console. > > > > > > Signed-off-by: Sherry Sun > > > --- > > > drivers/tty/serial/fsl_lpuart.c | 10 +++++----- > > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/tty/serial/fsl_lpuart.c > > > b/drivers/tty/serial/fsl_lpuart.c index 67fa113f77d4..7da46557fcb3 > > > 100644 > > > --- a/drivers/tty/serial/fsl_lpuart.c > > > +++ b/drivers/tty/serial/fsl_lpuart.c > > > @@ -2722,10 +2722,6 @@ static int lpuart_probe(struct platform_device > > *pdev) > > > handler = lpuart_int; > > > } > > > > > > - ret = lpuart_global_reset(sport); > > > - if (ret) > > > - goto failed_reset; > > > - > > > > So the problem with this being so early is uart_console() in > > lpuart_global_reset() that doesn't detect a console because sport->cons is > > not yet assigned? Couldn't that be worked around differently? > > > > Or is there something else in addition to that I'm missing? > > > Hi Ilpo, > > Yes, the root cause of the console cannot work after apply the commit > 60f361722ad2 ("serial: fsl_lpuart: Reset prior to registration") is > lpuart_global_reset() cannot identify the console port, so reset all > uart ports. This didn't answer my question. Is the main cause just lacking the ->cons from sport at this point which, I guess, could be just assigned from lpuart_reg similar to what uart_add_one_port() does before calling to reset? -- i. > Actually I've been thinking about any other workaround all afternoon, seems no other good options to me till now. And after a further check, I think the original patch is not needed, as uart_add_one_port() won't open the tty device, it should be safe to global reset the non-console ports after uart_add_one_port(). > > Best Regards > Sherry >