From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fl9Pr-0007lk-JK for linux-mtd@lists.infradead.org; Thu, 02 Aug 2018 08:57:05 +0000 From: Thomas Petazzoni To: Miquel Raynal , Boris Brezillon , Richard Weinberger , linux-mtd@lists.infradead.org, Marek Vasut , David Woodhouse , Brian Norris Cc: Ofer Heifetz , Thomas Petazzoni Subject: [PATCH v2] mtd: nand: use regmap_update_bits() in marvell_nand for syscon access Date: Thu, 2 Aug 2018 10:56:25 +0200 Message-Id: <20180802085625.29635-1-thomas.petazzoni@bootlin.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The marvell_nfc_init() function fiddles with some bits of a system controller on Armada 7K/8K. However, it does a read/modify/write sequence on GENCONF_CLK_GATING_CTRL and GENCONF_ND_CLK_CTRL, which isn't safe from a concurrency point of view, as the regmap lock isn't taken accross the read/modify/write sequence. To solve this issue, use regmap_update_bits(). While at it, since the "reg" variable is no longer needed for the read/modify/write sequences, get rid of it for the regmap_write() to GENCONF_SOC_DEVICE_MUX, and directly pass the value to be written as argument. Fixes: 02f26ecf8c772 ("mtd: nand: add reworked Marvell NAND controller driver") Signed-off-by: Thomas Petazzoni --- Changes since v1: - Add Fixes: tag - Drop the regmap_update_bits() for GENCONF_SOC_DEVICE_MUX, and keep regmap_write(). This patch is not Cc'ed to stable, because it doesn't qualify according to the rule "It must fix a real bug that bothers people (not a, "This could be a problem..." type thing)" mentioned in Documentation/process/stable-kernel-rules.rst. --- drivers/mtd/nand/raw/marvell_nand.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c index ebb1d141b900..65aadbfa1fe8 100644 --- a/drivers/mtd/nand/raw/marvell_nand.c +++ b/drivers/mtd/nand/raw/marvell_nand.c @@ -2691,24 +2691,23 @@ static int marvell_nfc_init(struct marvell_nfc *nfc) struct regmap *sysctrl_base = syscon_regmap_lookup_by_phandle(np, "marvell,system-controller"); - u32 reg; if (IS_ERR(sysctrl_base)) return PTR_ERR(sysctrl_base); - reg = GENCONF_SOC_DEVICE_MUX_NFC_EN | - GENCONF_SOC_DEVICE_MUX_ECC_CLK_RST | - GENCONF_SOC_DEVICE_MUX_ECC_CORE_RST | - GENCONF_SOC_DEVICE_MUX_NFC_INT_EN; - regmap_write(sysctrl_base, GENCONF_SOC_DEVICE_MUX, reg); + regmap_write(sysctrl_base, GENCONF_SOC_DEVICE_MUX, + GENCONF_SOC_DEVICE_MUX_NFC_EN | + GENCONF_SOC_DEVICE_MUX_ECC_CLK_RST | + GENCONF_SOC_DEVICE_MUX_ECC_CORE_RST | + GENCONF_SOC_DEVICE_MUX_NFC_INT_EN); - regmap_read(sysctrl_base, GENCONF_CLK_GATING_CTRL, ®); - reg |= GENCONF_CLK_GATING_CTRL_ND_GATE; - regmap_write(sysctrl_base, GENCONF_CLK_GATING_CTRL, reg); + regmap_update_bits(sysctrl_base, GENCONF_CLK_GATING_CTRL, + GENCONF_CLK_GATING_CTRL_ND_GATE, + GENCONF_CLK_GATING_CTRL_ND_GATE); - regmap_read(sysctrl_base, GENCONF_ND_CLK_CTRL, ®); - reg |= GENCONF_ND_CLK_CTRL_EN; - regmap_write(sysctrl_base, GENCONF_ND_CLK_CTRL, reg); + regmap_update_bits(sysctrl_base, GENCONF_ND_CLK_CTRL, + GENCONF_ND_CLK_CTRL_EN, + GENCONF_ND_CLK_CTRL_EN); } /* Configure the DMA if appropriate */ -- 2.14.4