From: Sowjanya Komatineni <skomatineni@nvidia.com>
Date: Fri, 16 Aug 2019 12:41:47 -0700
Subject: pinctrl: tegra: Flush pinctrl writes during resume

Git-commit: a4873accca0529b6a32e1ceb458be843cdea9ec6
Patch-mainline: v5.4-rc1
References: jsc#SLE-9391,jsc#SLE-9388,jsc#SLE-10608

This patch adds pinctrl register read to flush all the prior pinctrl
writes and then adds barrier for pinctrl register read to complete
during resume to make sure all pinctrl changes are effective.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Link: https://lore.kernel.org/r/1565984527-5272-3-git-send-email-skomatineni@nvidia.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/pinctrl/tegra/pinctrl-tegra.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
index 5e3c00137d71..e9a7cbb9aa33 100644
--- a/drivers/pinctrl/tegra/pinctrl-tegra.c
+++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
@@ -677,6 +677,10 @@ static int tegra_pinctrl_resume(struct device *dev)
 			writel_relaxed(*backup_regs++, regs++);
 	}
 
+	/* flush all the prior writes */
+	readl_relaxed(pmx->regs[0]);
+	/* wait for pinctrl register read to complete */
+	rmb();
 	return 0;
 }
 
-- 
2.16.4