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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 24DC5C433F5 for ; Mon, 27 Aug 2018 13:51:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBDCE208B8 for ; Mon, 27 Aug 2018 13:51:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CBDCE208B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=opensource.cirrus.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727430AbeH0RiF (ORCPT ); Mon, 27 Aug 2018 13:38:05 -0400 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:46822 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726883AbeH0RiE (ORCPT ); Mon, 27 Aug 2018 13:38:04 -0400 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7RDnZ42022400; Mon, 27 Aug 2018 08:51:19 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=rf@opensource.cirrus.com Received: from mail1.cirrus.com (mail1.cirrus.com [141.131.3.20]) by mx0a-001ae601.pphosted.com with ESMTP id 2m34h1tc7k-1; Mon, 27 Aug 2018 08:51:19 -0500 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail1.cirrus.com (Postfix) with ESMTP id 1145B611E126; Mon, 27 Aug 2018 08:51:19 -0500 (CDT) Received: from imbe.wolfsonmicro.main (198.61.95.81) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.408.0; Mon, 27 Aug 2018 14:51:18 +0100 Received: from edi-sw-dsktp006.ad.cirrus.com (edi-sw-dsktp006.ad.cirrus.com [198.90.251.121]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id w7RDpHoA007537; Mon, 27 Aug 2018 14:51:18 +0100 From: Richard Fitzgerald To: CC: , , "Richard Fitzgerald" Subject: [PATCH v2] mfd: madera: Don't use regmap_read_poll_timeout to poll for BOOT_DONE Date: Mon, 27 Aug 2018 14:51:15 +0100 Message-ID: <20180827135115.24231-1-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=841 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808270148 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While polling for BOOT_DONE the chip could NAK a read because it is still booting, which would terminate the regmap_read_poll_timeout() with an error. Instead implement a polling loop that ignores read errors so we always poll until the chip signals boot or the loop times out. Signed-off-by: Richard Fitzgerald --- drivers/mfd/madera-core.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index 8cfea969b060..440030cecbbd 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -132,32 +132,39 @@ const char *madera_name_from_type(enum madera_type type) } EXPORT_SYMBOL_GPL(madera_name_from_type); -#define MADERA_BOOT_POLL_MAX_INTERVAL_US 5000 -#define MADERA_BOOT_POLL_TIMEOUT_US 25000 +#define MADERA_BOOT_POLL_INTERVAL_USEC 5000 +#define MADERA_BOOT_POLL_TIMEOUT_USEC 25000 static int madera_wait_for_boot(struct madera *madera) { + ktime_t timeout; unsigned int val; - int ret; + int ret = 0; /* * We can't use an interrupt as we need to runtime resume to do so, * so we poll the status bit. This won't race with the interrupt * handler because it will be blocked on runtime resume. + * The chip could NAK a read request while it is booting so ignore + * errors from regmap_read. */ - ret = regmap_read_poll_timeout(madera->regmap, - MADERA_IRQ1_RAW_STATUS_1, - val, - (val & MADERA_BOOT_DONE_STS1), - MADERA_BOOT_POLL_MAX_INTERVAL_US, - MADERA_BOOT_POLL_TIMEOUT_US); - - if (ret) - dev_err(madera->dev, "Polling BOOT_DONE_STS failed: %d\n", ret); + timeout = ktime_add_us(ktime_get(), MADERA_BOOT_POLL_TIMEOUT_USEC); + regmap_read(madera->regmap, MADERA_IRQ1_RAW_STATUS_1, &val); + while (!(val & MADERA_BOOT_DONE_STS1) && + !ktime_after(ktime_get(), timeout)) { + usleep_range(MADERA_BOOT_POLL_INTERVAL_USEC / 2, + MADERA_BOOT_POLL_INTERVAL_USEC); + regmap_read(madera->regmap, MADERA_IRQ1_RAW_STATUS_1, &val); + }; + + if (!(val & MADERA_BOOT_DONE_STS1)) { + dev_err(madera->dev, "Polling BOOT_DONE_STS timed out\n"); + ret = -ETIMEDOUT; + } /* * BOOT_DONE defaults to unmasked on boot so we must ack it. - * Do this unconditionally to avoid interrupt storms. + * Do this even after a timeout to avoid interrupt storms. */ regmap_write(madera->regmap, MADERA_IRQ1_STATUS_1, MADERA_BOOT_DONE_EINT1); -- 2.11.0