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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 443EAC433E0 for ; Tue, 16 Feb 2021 20:54:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7F9864DFF for ; Tue, 16 Feb 2021 20:54:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229734AbhBPUyf (ORCPT ); Tue, 16 Feb 2021 15:54:35 -0500 Received: from z11.mailgun.us ([104.130.96.11]:50916 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbhBPUy1 (ORCPT ); Tue, 16 Feb 2021 15:54:27 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1613508849; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=vMW15tcB/VDtgwUABqW7aniqJwPV/31hchhXCEizb9w=; b=iSFBwicr9WTgcWaFj969SQMwGCZ/M+S9d/dMNrQGy+vHlzPJ07nd93nwSOHUQaIJK5lzNxQJ I4q9guTk3r5mQGvlxeUFyDb/9w9eeG/5CglUgpEnmz3AikctitrZ2QBMI+p7Gqfdr1+Jz0A5 DsKbZPoX8yEUwZ8U6o/oAE9T3zM= X-Mailgun-Sending-Ip: 104.130.96.11 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-east-1.postgun.com with SMTP id 602c30d3790422e0fe4fbff3 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 16 Feb 2021 20:53:39 GMT Sender: jhugo=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 3E141C433CA; Tue, 16 Feb 2021 20:53:39 +0000 (UTC) Received: from [10.226.59.216] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jhugo) by smtp.codeaurora.org (Postfix) with ESMTPSA id 2FA32C433C6; Tue, 16 Feb 2021 20:53:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 2FA32C433C6 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=fail smtp.mailfrom=jhugo@codeaurora.org Subject: Re: [PATCH] mhi_bus: core: Return EBUSY if MHI ring is full To: bbhatt@codeaurora.org Cc: manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Fan Wu , jhugo=codeaurora.org@codeaurora.org References: <1613501314-2392-1-git-send-email-jhugo@codeaurora.org> From: Jeffrey Hugo Message-ID: <5a6a77d2-fc67-753f-7b9f-4a60c808ac92@codeaurora.org> Date: Tue, 16 Feb 2021 13:53:37 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2/16/2021 1:22 PM, Bhaumik Bhatt wrote: > On 2021-02-16 10:48 AM, Jeffrey Hugo wrote: >> From: Fan Wu >> >> Currently ENOMEM is returned when MHI ring is full. This error code is >> very misleading. Change to EBUSY instead. >> >> Signed-off-by: Fan Wu >> Signed-off-by: Jeffrey Hugo >> --- >>  drivers/bus/mhi/core/main.c | 2 +- >>  1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c >> index f182736..21eb5fc 100644 >> --- a/drivers/bus/mhi/core/main.c >> +++ b/drivers/bus/mhi/core/main.c >> @@ -996,7 +996,7 @@ static int mhi_queue(struct mhi_device *mhi_dev, >> struct mhi_buf_info *buf_info, >> >>      ret = mhi_is_ring_full(mhi_cntrl, tre_ring); >>      if (unlikely(ret)) { >> -        ret = -ENOMEM; >> +        ret = -EBUSY; >>          goto exit_unlock; >>      } > > ENOMEM is descriptive of the state of the ring since you basically > cannot queue any > more packets as no memory is currently available. > > But I agree, it can be misleading for this API. How about EAGAIN in > place of EBUSY, > which tells the user to try the queue attempt again implying memory > should become > available as more elements are consumed by the device/client? Fan and I think EAGAIN is fine. Will send a v2. -- Jeffrey Hugo Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.