From patchwork Tue Nov 15 16:26:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frieder Schrempf X-Patchwork-Id: 20468 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp2823090wru; Tue, 15 Nov 2022 08:27:42 -0800 (PST) X-Google-Smtp-Source: AA0mqf6FNnJxP4JE6cRQWM2xwNGJyjcGGVTZ+EEaiR6mFzKgN6T6aGUi52odRkC+p1jectURU4B2 X-Received: by 2002:a17:90b:3c11:b0:218:8f2:5af9 with SMTP id pb17-20020a17090b3c1100b0021808f25af9mr1312850pjb.65.1668529662200; Tue, 15 Nov 2022 08:27:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1668529662; cv=none; d=google.com; s=arc-20160816; b=TCyWUaPwGg6V34yqSDU+YYdld7uOZbQk7e+JWzsw+af7tmCoheV0yh0SA3zczvXdmk MPXTaweZ/O6334Ri1n/V5Jw6hKL9xbdFZ1bEg11hWQCYKgi8X6eGaTmLmHTwh4NqQuBV 9KWGl2rCHBhDsGn6+zY7vZzP/9jXGVJ4W1iPwJszBXSxOyKcRbOFeiVnH+umjtmE+mQr E0nJqQLWgKcKqWL6t2rynxe4youOJkOZR4caUPAwSO79h5jKP9/kkM1KFumGAv0VKIRr iy7fkPh1bNa5pD0nR9ubMe8iGN7D4Zr3F9+ApPto4jsZP679rJHRh9ELGAyW4IVhMm03 Vhfw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=5tgKf+p7vookHNtY0coTIkhFiTMT/dbT9kfNLD5BJEk=; b=fILNle9xBTYY1Y+MgrsUtRnmzPTgTdCdE4C0Qt7JQBYWNcYunxZTD5dOWAwGBWzXUh gqOGPypTjto7e5Ck59F4V6yJebXqYlv81sofGijnHFGkgOXlkt7bCgvWpzzucTKq3JAa RmLUiguCoR9e1/bHXxO3omywHeT/1nQB8m4rZbJhZS7KUKqdrGghNM4SptFZvJ0NZnN8 2c9Pj8E5GmoX9DtFEkgvzbJUvpIwveFnTCBnQnAVzD/fPxNi9xh8HSFodzVu3DWqJX2s jgne2jNas3xAasfPtn7+SF0EEaVmmFPKQvWdcNBEdGbtaq+kIN0JXzUA7zdtyB51B/pk 4/Hw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@fris.de header.s=dkim header.b=PuDasNOC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=fris.de Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id pc5-20020a17090b3b8500b0021406fde039si15112423pjb.156.2022.11.15.08.27.28; Tue, 15 Nov 2022 08:27:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@fris.de header.s=dkim header.b=PuDasNOC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=fris.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238651AbiKOQ1P (ORCPT + 99 others); Tue, 15 Nov 2022 11:27:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238692AbiKOQ1G (ORCPT ); Tue, 15 Nov 2022 11:27:06 -0500 Received: from mail.fris.de (mail.fris.de [116.203.77.234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68A292496D; Tue, 15 Nov 2022 08:27:05 -0800 (PST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id BF9FBBFB36; Tue, 15 Nov 2022 17:26:59 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fris.de; s=dkim; t=1668529622; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding; bh=5tgKf+p7vookHNtY0coTIkhFiTMT/dbT9kfNLD5BJEk=; b=PuDasNOCxilEj2ZLt3Ng3PC9aw+m7AzQ5cN0UluxpTopBj4tpJTrnYEtTnC18ZtKpG3dpz LCKfShB4UHon957EwvINZUg4loKUD4fakqlFhGLIldq0yqwfkjXIUQqG96H4SQGz9VEbxJ Yi+TObf5Pr937nCfotNQXd3wjiIr1+PZ0f38G/9rDspqwhTbKaCb/5zlnZ/dFA8TPmFilH ZyI/17zlxT2M2xE2ADHgQfYobclQt9qbF0CQDEeyowEo4I8VHp4rSzM3YEHUUyuJCFhAkA Abg649ddL6Y3JRkoGlbYxqRl6tW7cu/QRl6VEWOb6V8Xbzz642tPBpofZqxTwQ== From: Frieder Schrempf To: David Jander , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, Marc Kleine-Budde , Mark Brown , Sascha Hauer , Shawn Guo Cc: Frieder Schrempf , Fabio Estevam , Marek Vasut , stable@vger.kernel.org, Baruch Siach , Minghao Chi , NXP Linux Team , Pengutronix Kernel Team Subject: [PATCH v2] spi: spi-imx: Fix spi_bus_clk if requested clock is higher than input clock Date: Tue, 15 Nov 2022 17:26:53 +0100 Message-Id: <20221115162654.2016820-1-frieder@fris.de> MIME-Version: 1.0 X-Last-TLS-Session-Version: TLSv1.3 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1749580042804360663?= X-GMAIL-MSGID: =?utf-8?q?1749580159208773474?= From: Frieder Schrempf In case the requested bus clock is higher than the input clock, the correct dividers (pre = 0, post = 0) are returned from mx51_ecspi_clkdiv(), but *fres is left uninitialized and therefore contains an arbitrary value. This causes trouble for the recently introduced PIO polling feature as the value in spi_imx->spi_bus_clk is used there to calculate for which transfers to enable PIO polling. Fix this by setting *fres even if no clock dividers are in use. This issue was observed on Kontron BL i.MX8MM with an SPI peripheral clock set to 50 MHz by default and a requested SPI bus clock of 80 MHz for the SPI NOR flash. With the fix applied the debug message from mx51_ecspi_clkdiv() now prints the following: spi_imx 30820000.spi: mx51_ecspi_clkdiv: fin: 50000000, fspi: 50000000, post: 0, pre: 0 Fixes: 07e759387788 ("spi: spi-imx: add PIO polling support") Cc: Marc Kleine-Budde Cc: David Jander Cc: Fabio Estevam Cc: Mark Brown Cc: Marek Vasut Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf Tested-by: Fabio Estevam --- Changes for v2: * Remove the reference and the Fixes tag for commit 6fd8b8503a0d as it is incorrect. --- drivers/spi/spi-imx.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 30d82cc7300b..468ce0a2b282 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -444,8 +444,7 @@ static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx, unsigned int pre, post; unsigned int fin = spi_imx->spi_clk; - if (unlikely(fspi > fin)) - return 0; + fspi = min(fspi, fin); post = fls(fin) - fls(fspi); if (fin > fspi << post)