From patchwork Wed Sep 9 22:28:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eddie James X-Patchwork-Id: 11766307 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9835F92C for ; Wed, 9 Sep 2020 22:29:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CE0920C09 for ; Wed, 9 Sep 2020 22:29:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="tr8bt4XK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729525AbgIIW3P (ORCPT ); Wed, 9 Sep 2020 18:29:15 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:57834 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729161AbgIIW3K (ORCPT ); Wed, 9 Sep 2020 18:29:10 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 089M3DDD183868; Wed, 9 Sep 2020 18:29:02 -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=idlvgwGq0L5gVIChTX8J5i+iGSAiTqdOo2r6/m3Cebc=; b=tr8bt4XKqIP71RfixUNGSEoiyHyk1gqhkuDy6TwS6levZB6vUnSZUIY40ckckzdOTJYR 0Y0/r6cCuHZKocJwhnq75f53jDKq53Sp6XilK+nBJVmCBfPP2gKvy7mqbLbSqdXYx9K3 lEUjTUQyATWkLox9ZPOtQBcyjwIKnoIb/DAP2VY+mepBPj6yfF1wTjlL4RCwNavZjb/g TPhnl4p1CZIS80B8VrLs8uM9sADSBa+4+8XAGeL2uk5aK8ZsYWTGYE1LBXS3yXGwq8Mm +XKvLJQoBFB9gtX9ldbQlNqjB/N1ZfhM+cnyTf2XYo56LizYQ88f2oeLpY3ww24WdoOh Dg== Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 33f7abgxm9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 09 Sep 2020 18:29:02 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 089MS9tN015047; Wed, 9 Sep 2020 22:29:01 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma04dal.us.ibm.com with ESMTP id 33c2a9kd7b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 09 Sep 2020 22:29:01 +0000 Received: from b03ledav002.gho.boulder.ibm.com (b03ledav002.gho.boulder.ibm.com [9.17.130.233]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 089MT0Us62915054 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 9 Sep 2020 22:29:00 GMT Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 07FDD136051; Wed, 9 Sep 2020 22:29:00 +0000 (GMT) Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 82B2A136055; Wed, 9 Sep 2020 22:28:59 +0000 (GMT) Received: from SHADE6A.ibmuc.com (unknown [9.163.76.239]) by b03ledav002.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 9 Sep 2020 22:28:59 +0000 (GMT) From: Eddie James To: linux-spi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, joel@jms.id.au, broonie@kernel.org, bradleyb@fuzziesquirrel.com, robh+dt@kernel.org, arnd@arndb.de, eajames@linux.ibm.com Subject: [PATCH v2 2/6] spi: fsi: Fix clock running too fast Date: Wed, 9 Sep 2020 17:28:53 -0500 Message-Id: <20200909222857.28653-3-eajames@linux.ibm.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200909222857.28653-1-eajames@linux.ibm.com> References: <20200909222857.28653-1-eajames@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-09_17:2020-09-09,2020-09-09 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 bulkscore=0 mlxlogscore=999 suspectscore=1 lowpriorityscore=0 malwarescore=0 mlxscore=0 adultscore=0 clxscore=1015 phishscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009090192 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org From: Brad Bishop Use a clock divider tuned to a 200MHz FSI bus frequency (the maximum). Use of the previous divider at 200MHz results in corrupt data from endpoint devices. Ideally the clock divider would be calculated from the FSI clock, but that would require some significant work on the FSI driver. With FSI frequencies slower than 200MHz, the SPI clock will simply run slower, but safely. Signed-off-by: Brad Bishop Signed-off-by: Eddie James Signed-off-by: Joel Stanley --- drivers/spi/spi-fsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index 8f64af0140e0..559d0ff981f3 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -350,7 +350,7 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx) u64 status = 0ULL; u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE | SPI_FSI_CLOCK_CFG_SCK_NO_DEL | - FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 4); + FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19); end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS); do {