[PATCH] pinctrl: single: fix bias pull up/down handling in pin_config_set

[Chi Zhang]

In the pin_config_set function, when handling PIN_CONFIG_BIAS_PULL_DOWN or
PIN_CONFIG_BIAS_PULL_UP, the function calls pcs_pinconf_clear_bias()
which writes the register. However, the subsequent operations continue
using the stale 'data' value from before the register write, effectively
causing the bias clear operation to be overwritten and not take effect.

Fix this by reading the 'data' value from the register after calling
pcs_pinconf_clear_bias().

This bug seems to have existed when this code was first merged in commit
9dddb4df90d1 ("pinctrl: single: support generic pinconf").

Signed-off-by: Chi Zhang <chizhang at asrmicro.com>
---
 drivers/pinctrl/pinctrl-single.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index 5cda6201b60f..8aedee2720bc 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -589,8 +589,10 @@ static int pcs_pinconf_set(struct pinctrl_dev *pctldev,
 			/* 4 parameters */
 			case PIN_CONFIG_BIAS_PULL_DOWN:
 			case PIN_CONFIG_BIAS_PULL_UP:
-				if (arg)
+				if (arg) {
 					pcs_pinconf_clear_bias(pctldev, pin);
+					data = pcs->read(pcs->base + offset);
+				}
 				fallthrough;
 			case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
 				data &= ~func->conf[i].mask;
-- 
2.17.1