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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02587C54EBE for ; Mon, 16 Jan 2023 16:28:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233171AbjAPQ2D (ORCPT ); Mon, 16 Jan 2023 11:28:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233075AbjAPQ1i (ORCPT ); Mon, 16 Jan 2023 11:27:38 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 563B323DA5 for ; Mon, 16 Jan 2023 08:16:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4C84860FDF for ; Mon, 16 Jan 2023 16:16:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61AACC433D2; Mon, 16 Jan 2023 16:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673885761; bh=NnjV2ND8Fib1hz1Evw0shan0XBpb9qeocdoMvfE6E9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=heVYKequPZ58eMMQkrWlqYHHQI01p5zKbtRmmJb1t5rN5/f4dgH9wPuGYOpxesWTq ArQ1qTOAUkzHBrp3/JEq8ue6LVRwmLI9l5jILCBcn1EnjgLXdRw2bnutFdD432mHJ6 7PGJshU5tKxzjetIkHFX0BBARQwDToL4ojpU7TXk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexander Sverdlin , Mark Brown , Sasha Levin Subject: [PATCH 5.4 174/658] spi: spidev: mask SPI_CS_HIGH in SPI_IOC_RD_MODE Date: Mon, 16 Jan 2023 16:44:22 +0100 Message-Id: <20230116154917.434771385@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154909.645460653@linuxfoundation.org> References: <20230116154909.645460653@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Sverdlin [ Upstream commit 7dbfa445ff7393d1c4c066c1727c9e0af1251958 ] Commit f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") has changed the user-space interface so that bogus SPI_CS_HIGH started to appear in the mask returned by SPI_IOC_RD_MODE even for active-low CS pins. Commit 138c9c32f090 ("spi: spidev: Fix CS polarity if GPIO descriptors are used") fixed only SPI_IOC_WR_MODE part of the problem. Let's fix SPI_IOC_RD_MODE symmetrically. Test case: #include #include #include int main(int argc, char **argv) { char modew = SPI_CPHA; char moder; int f = open("/dev/spidev0.0", O_RDWR); if (f < 0) return 1; ioctl(f, SPI_IOC_WR_MODE, &modew); ioctl(f, SPI_IOC_RD_MODE, &moder); return moder == modew ? 0 : 2; } Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") Signed-off-by: Alexander Sverdlin Link: https://lore.kernel.org/r/20221130162927.539512-1-alexander.sverdlin@siemens.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spidev.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index be503a0e6ef7..2478ae471f4e 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -373,12 +373,23 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) switch (cmd) { /* read requests */ case SPI_IOC_RD_MODE: - retval = put_user(spi->mode & SPI_MODE_MASK, - (__u8 __user *)arg); - break; case SPI_IOC_RD_MODE32: - retval = put_user(spi->mode & SPI_MODE_MASK, - (__u32 __user *)arg); + tmp = spi->mode; + + { + struct spi_controller *ctlr = spi->controller; + + if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods && + ctlr->cs_gpiods[spi->chip_select]) + tmp &= ~SPI_CS_HIGH; + } + + if (cmd == SPI_IOC_RD_MODE) + retval = put_user(tmp & SPI_MODE_MASK, + (__u8 __user *)arg); + else + retval = put_user(tmp & SPI_MODE_MASK, + (__u32 __user *)arg); break; case SPI_IOC_RD_LSB_FIRST: retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, -- 2.35.1