From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AAD73749A for ; Thu, 12 Jan 2023 14:11:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B8A8C433D2; Thu, 12 Jan 2023 14:11:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673532683; bh=9g3w6FqGG5dKfjDgxqMNoBNcBj3pFG2i7rm2kfMKH0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BX2WOiPhko+7C7ucZKLQwL6pwwxsCbx7Kr24anmY//ZqQR323iSSCO/G2SNX3PF85 usUt5cJSqXPx8wHiBarrjR7w7VecV/4bcXyS2FOq8RPJ/mCdzJouYFcA16b3KDsIM7 462lk4yUecxrHicBcmwniwXXfx5tAYMDn/hASAFE= 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 5.10 201/783] spi: spidev: mask SPI_CS_HIGH in SPI_IOC_RD_MODE Date: Thu, 12 Jan 2023 14:48:37 +0100 Message-Id: <20230112135533.657723768@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 859910ec8d9f..9c5ec99431d2 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -376,12 +376,23 @@ 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