From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:36918 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752910AbeBBRHC (ORCPT ); Fri, 2 Feb 2018 12:07:02 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Agner , Mark Brown Subject: [PATCH 4.9 86/86] spi: imx: do not access registers while clocks disabled Date: Fri, 2 Feb 2018 17:58:46 +0100 Message-Id: <20180202140830.666019664@linuxfoundation.org> In-Reply-To: <20180202140822.679101338@linuxfoundation.org> References: <20180202140822.679101338@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Agner commit d593574aff0ab846136190b1729c151c736727ec upstream. Since clocks are disabled except during message transfer clocks are also disabled when spi_imx_remove gets called. Accessing registers leads to a freeeze at least on a i.MX 6ULL. Enable clocks before disabling accessing the MXC_CSPICTRL register. Fixes: 9e556dcc55774 ("spi: spi-imx: only enable the clocks when we start to transfer a message") Signed-off-by: Stefan Agner Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-imx.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -1307,12 +1307,23 @@ static int spi_imx_remove(struct platfor { struct spi_master *master = platform_get_drvdata(pdev); struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + int ret; spi_bitbang_stop(&spi_imx->bitbang); + ret = clk_enable(spi_imx->clk_per); + if (ret) + return ret; + + ret = clk_enable(spi_imx->clk_ipg); + if (ret) { + clk_disable(spi_imx->clk_per); + return ret; + } + writel(0, spi_imx->base + MXC_CSPICTRL); - clk_unprepare(spi_imx->clk_ipg); - clk_unprepare(spi_imx->clk_per); + clk_disable_unprepare(spi_imx->clk_ipg); + clk_disable_unprepare(spi_imx->clk_per); spi_imx_sdma_exit(spi_imx); spi_master_put(master);