From: Sowjanya Komatineni <skomatineni@xxxxxxxxxx> [ Upstream commit c2cf351eba2ff6002ce8eb178452219d2521e38e ] 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 <treding@xxxxxxxxxx> Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx> Link: https://lore.kernel.org/r/1565984527-5272-2-git-send-email-skomatineni@xxxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 abcfbad94f00e..849c3b34e887c 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) -- 2.20.1
