From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowjanya Komatineni Subject: [PATCH v9 01/22] pinctrl: tegra: Fix write barrier placement in pmx_writel Date: Fri, 16 Aug 2019 12:41:46 -0700 Message-ID: <1565984527-5272-2-git-send-email-skomatineni@nvidia.com> References: <1565984527-5272-1-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1565984527-5272-1-git-send-email-skomatineni@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: thierry.reding@gmail.com, jonathanh@nvidia.com, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, skomatineni@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, digetx@gmail.com, devicetree@vger.kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, linux-pm@vger.kernel.org List-Id: devicetree@vger.kernel.org pmx_writel uses writel which inserts write barrier before the register write. This patch has fix to replace writel with writel_relaxed followed by a readback and memory barrier to ensure write operation is completed for successful pinctrl change. Acked-by: Thierry Reding Reviewed-by: Dmitry Osipenko Signed-off-by: Sowjanya Komatineni --- drivers/pinctrl/tegra/pinctrl-tegra.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c index e3a237534281..5e3c00137d71 100644 --- a/drivers/pinctrl/tegra/pinctrl-tegra.c +++ b/drivers/pinctrl/tegra/pinctrl-tegra.c @@ -32,7 +32,9 @@ static inline u32 pmx_readl(struct tegra_pmx *pmx, u32 bank, u32 reg) static inline void pmx_writel(struct tegra_pmx *pmx, u32 val, u32 bank, u32 reg) { - writel(val, pmx->regs[bank] + reg); + writel_relaxed(val, pmx->regs[bank] + reg); + /* make sure pinmux register write completed */ + pmx_readl(pmx, bank, reg); } static int tegra_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) -- 2.7.4