From patchwork Tue Dec 27 10:04:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ivan Bornyakov X-Patchwork-Id: 13082184 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 742EBC4332F for ; Tue, 27 Dec 2022 10:09:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230492AbiL0KHc (ORCPT ); Tue, 27 Dec 2022 05:07:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiL0KHa (ORCPT ); Tue, 27 Dec 2022 05:07:30 -0500 Received: from mail.pr-group.ru (mail.pr-group.ru [178.18.215.3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 159062FF; Tue, 27 Dec 2022 02:07:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=metrotek.ru; s=mail; h=from:subject:date:message-id:to:cc:mime-version:content-transfer-encoding: in-reply-to:references; bh=7Fvs78gYqrEVBbbQ/K9bc20z+/joLO6qDiw854CBaFQ=; b=SLvWAWwm+e3kVkiocTYSH6yr8Rs4Gu5Kc7UcGaV7cR8Y2jyWu/puOUzaEXH20HRVtNx9mlnWJzec4 zdOKRm6SM1RgM450cjqAla6xG9c0haKUEfj+zz3xCcarc1GcXMjEctepRhxzJ5kvfBUfewGJQqGeUt A1gEE7ClAEUMMcpJmE24UriX0i3Nr+sDyJKYGOFP4FIKCA3PJWUl2mbOAdPRDBnx9O5CbS5PPt3B+y 3zkd5uhPxNRLBm7H5x5D1MNeQIIGR/vXoAx7okkvsGyQgyvHMRLoSKwh2j5+GKvL7dPY+29ZJXvJSu JdFwuUq63RVjs8cplssk17HQsG8u/RQ== X-Kerio-Anti-Spam: Build: [Engines: 2.16.5.1460, Stamp: 3], Multi: [Enabled, t: (0.000010,0.012862)], BW: [Enabled, t: (0.000031,0.000002)], RTDA: [Enabled, t: (0.094436), Hit: No, Details: v2.42.0; Id: 15.52ka2l.1gl9gppe8.3nj; mclb], total: 0(700) X-Footer: bWV0cm90ZWsucnU= Received: from localhost.localdomain ([78.37.162.181]) (authenticated user i.bornyakov@metrotek.ru) by mail.pr-group.ru with ESMTPSA (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256 bits)); Tue, 27 Dec 2022 13:07:10 +0300 From: Ivan Bornyakov To: Conor Dooley , Moritz Fischer , Wu Hao , Xu Yilun , Tom Rix , =?utf-8?q?Ilpo_J?= =?utf-8?q?=C3=A4rvinen?= Cc: Ivan Bornyakov , linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, system@metrotek.ru Subject: [PATCH v3 2/3] fpga: microchip-spi: rewrite status polling in a time measurable way Date: Tue, 27 Dec 2022 13:04:49 +0300 Message-Id: <20221227100450.2257-3-i.bornyakov@metrotek.ru> X-Mailer: git-send-email 2.38.2 In-Reply-To: <20221227100450.2257-1-i.bornyakov@metrotek.ru> References: <20221227100450.2257-1-i.bornyakov@metrotek.ru> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org Original busy loop with retries count in mpf_poll_status() is not too reliable, as it takes different times on different systems. Replace it with read_poll_timeout() macro. While at it, fix polling stop condition to met function's original intention declared in the comment. The issue with original polling stop condition is that it stops if any of mask bits is set, while intention was to stop if all mask bits is set. This was not noticible because only MPF_STATUS_READY is passed as mask argument and it is BIT(1). Fixes: 5f8d4a900830 ("fpga: microchip-spi: add Microchip MPF FPGA manager") Signed-off-by: Ivan Bornyakov Reviewed-by: Ilpo Järvinen Acked-by: Conor Dooley --- drivers/fpga/microchip-spi.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/drivers/fpga/microchip-spi.c b/drivers/fpga/microchip-spi.c index e72fedd93a27..8d1d9476d0cc 100644 --- a/drivers/fpga/microchip-spi.c +++ b/drivers/fpga/microchip-spi.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -33,7 +34,7 @@ #define MPF_BITS_PER_COMPONENT_SIZE 22 -#define MPF_STATUS_POLL_RETRIES 10000 +#define MPF_STATUS_POLL_TIMEOUT (2 * USEC_PER_SEC) #define MPF_STATUS_BUSY BIT(0) #define MPF_STATUS_READY BIT(1) #define MPF_STATUS_SPI_VIOLATION BIT(2) @@ -197,21 +198,16 @@ static int mpf_ops_parse_header(struct fpga_manager *mgr, /* Poll HW status until busy bit is cleared and mask bits are set. */ static int mpf_poll_status(struct mpf_priv *priv, u8 mask) { - int status, retries = MPF_STATUS_POLL_RETRIES; + int ret, status; - while (retries--) { - status = mpf_read_status(priv); - if (status < 0) - return status; - - if (status & MPF_STATUS_BUSY) - continue; - - if (!mask || (status & mask)) - return status; - } + ret = read_poll_timeout(mpf_read_status, status, + (status < 0) || + ((status & (MPF_STATUS_BUSY | mask)) == mask), + 0, MPF_STATUS_POLL_TIMEOUT, false, priv); + if (ret < 0) + return ret; - return -EBUSY; + return status; } static int mpf_spi_write(struct mpf_priv *priv, const void *buf, size_t buf_size)