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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E90ADC433E0 for ; Thu, 14 May 2020 13:33:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C76D82065D for ; Thu, 14 May 2020 13:33:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="xBeG4wZx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726304AbgENNdd (ORCPT ); Thu, 14 May 2020 09:33:33 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:31338 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726056AbgENNdc (ORCPT ); Thu, 14 May 2020 09:33:32 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1589463212; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=TZPgL+XkybaeeYUYsbnJMPveHMNejUHVe64o0zrFwys=; b=xBeG4wZxUSGeSJ4Fqc0kSsGI8sOlTi2Z4CGi6ZLuXjEetnCrhBN9dm2cJda1ehJQR4g4zhAf e/2Pa38spTX2FH9L3+4VCePsxyXbAxkzPIothY3UIU6nUEr0PMJRvghOk2uzU9ufi1FJpNCq kGOUz7IusChxyPguTpcUZ86Or04= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyIzZmY0MiIsICJsaW51eC1zZXJpYWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ebd48a7.7f82d40b3d18-smtp-out-n05; Thu, 14 May 2020 13:33:27 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id AE280C43636; Thu, 14 May 2020 13:33:27 +0000 (UTC) Received: from [192.168.0.4] (unknown [124.123.29.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: msavaliy) by smtp.codeaurora.org (Postfix) with ESMTPSA id 88078C432C2; Thu, 14 May 2020 13:33:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 88078C432C2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=msavaliy@codeaurora.org Subject: Re: [PATCH V2] serial: msm_geni_serial_console : Add Earlycon support To: Greg KH Cc: akashast@codeaurora.org, linux-serial@vger.kernel.org, saravanak@google.com, sspatil@google.com, tkjos@google.com References: <20200506113331.32562-1-msavaliy@codeaurora.org> <20200506120532.GB3047211@kroah.com> From: "Mukesh, Savaliya" Message-ID: <572765da-6dae-3056-3fc2-188b92291777@codeaurora.org> Date: Thu, 14 May 2020 19:03:18 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200506120532.GB3047211@kroah.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On 5/6/2020 5:35 PM, Greg KH wrote: > On Wed, May 06, 2020 at 05:03:31PM +0530, Mukesh, Savaliya wrote: >> + /* >> + * If the WM bit never set, then the Tx state machine is not >> + * in a valid state, so break, cancel/abort any existing >> + * command. Unfortunately the current data being written is >> + * lost. >> + */ >> + while (!msm_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, >> + M_TX_FIFO_WATERMARK_EN, true)) >> + break; > Am I reading this correctly in that if the bit is set properly, you will > just loop for forever? > > That feels wrong, are you sure this is correct? It seems correct to me. The API returns true if function sees the BIT is set else returns false. Mostly it's true and returns true, hence it shouldn't loop. > >> + chars_to_write = min((unsigned int)(count - i), >> + avail_fifo_bytes); >> + if ((chars_to_write << 1) > avail_fifo_bytes) >> + chars_to_write = (avail_fifo_bytes >> 1); >> + uart_console_write(uport, (s + i), chars_to_write, >> + msm_geni_serial_wr_char); >> + writel_relaxed(M_TX_FIFO_WATERMARK_EN, >> + uport->membase+SE_GENI_M_IRQ_CLEAR); >> + /* Ensure this goes through before polling for WM IRQ again.*/ >> + mb(); > Again, writel() on its own should be fine here, and elsewhere. Removed mb() from whole file as _relaxed takes care of it. > > thanks, > > greg k-h