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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B7EFFC433E1 for ; Thu, 20 Aug 2020 17:03:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AD88208B3 for ; Thu, 20 Aug 2020 17:03:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="kKuVEVlm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729902AbgHTRDo (ORCPT ); Thu, 20 Aug 2020 13:03:44 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57766 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730068AbgHTRCs (ORCPT ); Thu, 20 Aug 2020 13:02:48 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07KH1UCK134262; Thu, 20 Aug 2020 13:02:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=j/oDWsRv895s55NF1YbL3HUUtH7qtXG3XNnJHAmUmGY=; b=kKuVEVlmxtyvZBTknwfXOOXvRe4Eu7uYqolxWWqfOH6aVDrnPQ0UYQNUabtkyIGC5qsa fbbm1/N/eX30sFh0xlPjGsIYIgL6ItsPgTWmI5o75kz90YyWlDNkWaKC/I7MJQv9gnqM bjYRA3O+NeblkCdc30JIGmw81rA4hb+ZKaIH0uSPTIzK9i/GqqvQ05pLWuRLPE7z+FN4 I4BufddVO/G2U0luQC7skXkyBuoBXo5V4PMfD5EOAzQ0bWq1MF+3RMWNfvke7CKrVVOl twvK0N6OQbvu4k4e70gnymwjceoAA673ijqJT1ia6BPMURzSEQkKF22d5wPwAPKLzjKy fA== Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0b-001b2d01.pphosted.com with ESMTP id 331ugy3fdf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 20 Aug 2020 13:02:42 -0400 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 07KH0guK015112; Thu, 20 Aug 2020 17:02:38 GMT Received: from b01cxnp22033.gho.pok.ibm.com (b01cxnp22033.gho.pok.ibm.com [9.57.198.23]) by ppma04wdc.us.ibm.com with ESMTP id 3304uewqq1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 20 Aug 2020 17:02:38 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 07KH2coK43188680 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 20 Aug 2020 17:02:38 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 14170AE05C; Thu, 20 Aug 2020 17:02:38 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 29DADAE060; Thu, 20 Aug 2020 17:02:37 +0000 (GMT) Received: from SHADE6A.ibmuc.com (unknown [9.163.70.74]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 20 Aug 2020 17:02:37 +0000 (GMT) From: Eddie James To: linux-spi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, eajames@linux.ibm.com, joel@jms.id.au, bradleyb@fuzziesquirrel.com, broonie@kernel.org, robh+dt@kernel.org, arnd@arndb.de Subject: [PATCH 7/7] eeprom: at25: Split reads into chunks and cap write size Date: Thu, 20 Aug 2020 12:02:28 -0500 Message-Id: <20200820170228.42053-8-eajames@linux.ibm.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200820170228.42053-1-eajames@linux.ibm.com> References: <20200820170228.42053-1-eajames@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-20_03:2020-08-19,2020-08-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 malwarescore=0 bulkscore=0 impostorscore=0 suspectscore=1 phishscore=0 priorityscore=1501 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008200135 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Brad Bishop Make use of spi_max_transfer_size to avoid requesting transfers that are too large for some spi controllers. Signed-off-by: Brad Bishop Signed-off-by: Eddie James Signed-off-by: Joel Stanley --- drivers/misc/eeprom/at25.c | 94 ++++++++++++++++++++++---------------- 1 file changed, 54 insertions(+), 40 deletions(-) diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index ed8d38b09925..30f0704ab2d4 100644 --- a/drivers/misc/eeprom/at25.c +++ b/drivers/misc/eeprom/at25.c @@ -64,12 +64,17 @@ static int at25_ee_read(void *priv, unsigned int offset, { struct at25_data *at25 = priv; char *buf = val; + size_t max_chunk = spi_max_transfer_size(at25->spi); + size_t num_msgs = DIV_ROUND_UP(count, max_chunk); + size_t nr_bytes = 0; u8 command[EE_MAXADDRLEN + 1]; u8 *cp; ssize_t status; struct spi_transfer t[2]; struct spi_message m; u8 instr; + unsigned int msg_offset; + size_t msg_count; if (unlikely(offset >= at25->chip.byte_len)) return -EINVAL; @@ -78,57 +83,64 @@ static int at25_ee_read(void *priv, unsigned int offset, if (unlikely(!count)) return -EINVAL; - cp = command; - - instr = AT25_READ; - if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR) - if (offset >= (1U << (at25->addrlen * 8))) - instr |= AT25_INSTR_BIT3; - *cp++ = instr; - - /* 8/16/24-bit address is written MSB first */ - switch (at25->addrlen) { - default: /* case 3 */ - *cp++ = offset >> 16; - fallthrough; - case 2: - *cp++ = offset >> 8; - fallthrough; - case 1: - case 0: /* can't happen: for better codegen */ - *cp++ = offset >> 0; - } + msg_offset = (unsigned int)offset; + msg_count = min(count, max_chunk); + while (num_msgs) { + cp = command; + + instr = AT25_READ; + if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR) + if (msg_offset >= (1U << (at25->addrlen * 8))) + instr |= AT25_INSTR_BIT3; + *cp++ = instr; + + /* 8/16/24-bit address is written MSB first */ + switch (at25->addrlen) { + default: /* case 3 */ + *cp++ = msg_offset >> 16; + fallthrough; + case 2: + *cp++ = msg_offset >> 8; + fallthrough; + case 1: + case 0: /* can't happen: for better codegen */ + *cp++ = msg_offset >> 0; + } - spi_message_init(&m); - memset(t, 0, sizeof(t)); + spi_message_init(&m); + memset(t, 0, sizeof(t)); - t[0].tx_buf = command; - t[0].len = at25->addrlen + 1; - spi_message_add_tail(&t[0], &m); + t[0].tx_buf = command; + t[0].len = at25->addrlen + 1; + spi_message_add_tail(&t[0], &m); - t[1].rx_buf = buf; - t[1].len = count; - spi_message_add_tail(&t[1], &m); + t[1].rx_buf = buf + nr_bytes; + t[1].len = msg_count; + spi_message_add_tail(&t[1], &m); - mutex_lock(&at25->lock); + mutex_lock(&at25->lock); - /* Read it all at once. - * - * REVISIT that's potentially a problem with large chips, if - * other devices on the bus need to be accessed regularly or - * this chip is clocked very slowly - */ - status = spi_sync(at25->spi, &m); - dev_dbg(&at25->spi->dev, "read %zu bytes at %d --> %zd\n", - count, offset, status); + status = spi_sync(at25->spi, &m); - mutex_unlock(&at25->lock); - return status; + mutex_unlock(&at25->lock); + + if (status) + return status; + + --num_msgs; + msg_offset += msg_count; + nr_bytes += msg_count; + } + + dev_dbg(&at25->spi->dev, "read %zu bytes at %d\n", + count, offset); + return 0; } static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count) { struct at25_data *at25 = priv; + size_t maxsz = spi_max_transfer_size(at25->spi); const char *buf = val; int status = 0; unsigned buf_size; @@ -191,6 +203,8 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count) segment = buf_size - (offset % buf_size); if (segment > count) segment = count; + if (segment > maxsz) + segment = maxsz; memcpy(cp, buf, segment); status = spi_write(at25->spi, bounce, segment + at25->addrlen + 1); -- 2.26.2