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 5C875EB64DC for ; Thu, 22 Jun 2023 19:49:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229682AbjFVTtD (ORCPT ); Thu, 22 Jun 2023 15:49:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229743AbjFVTtC (ORCPT ); Thu, 22 Jun 2023 15:49:02 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2324F1FE8; Thu, 22 Jun 2023 12:49:01 -0700 (PDT) Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35MJFd5R000374; Thu, 22 Jun 2023 19:48:39 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=tmENBKFGIrm+W5xEE+TLaiJBxZpQvSPgrr9e7uSqw6o=; b=aaMWb/ztQ97ox+3GJcQ5L1iF4TeUEePjpAuwT+oWW6eVqhVuyWeJ1rCE8loGnU0Oy94n B4ZGsWuUvCNo3tZuRJfuCdSYoL/W2+2a+peBnSbzkt/sh6f12JmqdHeGKa+S7R+HZzo+ x22acOUCjFkCUS2907Z27Et7sXE+u8rQowh7oNifJdL1HwA2bxf6K06gHmC6hS2y261W Jcq5MWHXt4iE3OwHhbV8XJkVQZTFeR3feTKBVg7P0BMN78mTfoR063lMtREUzRzFGDQh OUq15CsGZDCYoD/f7RkJUzrJVUIzPPSMZlBCRK5Sq9qM73kvjpkFP1On+l+37OBZHFhw GA== Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3rcva1gmqu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Jun 2023 19:48:39 +0000 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 35MJbDXX010301; Thu, 22 Jun 2023 19:48:38 GMT Received: from smtprelay06.wdc07v.mail.ibm.com ([9.208.129.118]) by ppma04dal.us.ibm.com (PPS) with ESMTPS id 3r94f726ac-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Jun 2023 19:48:38 +0000 Received: from smtpav02.dal12v.mail.ibm.com (smtpav02.dal12v.mail.ibm.com [10.241.53.101]) by smtprelay06.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 35MJmaoV65339684 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 22 Jun 2023 19:48:37 GMT Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9D77858051; Thu, 22 Jun 2023 19:48:36 +0000 (GMT) Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5994C5805C; Thu, 22 Jun 2023 19:48:36 +0000 (GMT) Received: from [9.61.34.182] (unknown [9.61.34.182]) by smtpav02.dal12v.mail.ibm.com (Postfix) with ESMTP; Thu, 22 Jun 2023 19:48:36 +0000 (GMT) Message-ID: <6dff003d-c727-e4a3-b5d3-f58beb2b02cb@linux.ibm.com> Date: Thu, 22 Jun 2023 14:48:36 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v2 3/4] spi: Split transfers larger than max size To: Vincent Whitchurch , broonie@kernel.org, krzysztof.kozlowski@linaro.org, andi@etezian.org Cc: kernel@axis.com, alim.akhtar@samsung.com, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20220927112117.77599-1-vincent.whitchurch@axis.com> <20220927112117.77599-4-vincent.whitchurch@axis.com> Content-Language: en-US From: Eddie James In-Reply-To: <20220927112117.77599-4-vincent.whitchurch@axis.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: UGpeUflZAMyn6SP0xeEJT2IivBDUQeK2 X-Proofpoint-ORIG-GUID: UGpeUflZAMyn6SP0xeEJT2IivBDUQeK2 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-06-22_14,2023-06-22_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 clxscore=1011 phishscore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 malwarescore=0 spamscore=0 priorityscore=1501 suspectscore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306220167 Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On 9/27/22 06:21, Vincent Whitchurch wrote: > A couple of drivers call spi_split_transfers_maxsize() from their > ->prepare_message() callbacks to split transfers which are too big for > them to handle. Add support in the core to do this based on > ->max_transfer_size() to avoid code duplication. Hello, I've been testing AT25 functionality in linux 6.1 and I believe this patch is breaking the AT25 protocol. It will split a write command up such that some of the data is in a different transfer than  the write enable and address. According to my understanding of the AT25 spec, that doesn't work... Someone correct me if I'm wrong though. Do we need a flag to enable/disable this behavior depending on the client perhaps? Thanks, Eddie > > Signed-off-by: Vincent Whitchurch > --- > drivers/spi/spi.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index f41a8c2752b8..44e4352d948b 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -1649,6 +1649,15 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, > > trace_spi_message_start(msg); > > + ret = spi_split_transfers_maxsize(ctlr, msg, > + spi_max_transfer_size(msg->spi), > + GFP_KERNEL | GFP_DMA); > + if (ret) { > + msg->status = ret; > + spi_finalize_current_message(ctlr); > + return ret; > + } > + > if (ctlr->prepare_message) { > ret = ctlr->prepare_message(ctlr, msg); > if (ret) {