linux-kernel - Re: [PATCH 2/7] pinctrl: mediatek: paris: Fix PIN_CONFIG_BIAS

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Date:   Wed, 19 Jan 2022 09:42:46 +0800
From:   Guodong Liu <guodong.liu@...iatek.com>
To:     Chen-Yu Tsai <wenst@...omium.org>,
        Sean Wang <sean.wang@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Matthias Brugger <matthias.bgg@...il.com>
CC:     <linux-mediatek@...ts.infradead.org>, <linux-gpio@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        "Zhiyong Tao" <zhiyong.tao@...iatek.com>,
        Hui Liu <hui.liu@...iatek.com>,
        Light Hsieh <light.hsieh@...iatek.com>
Subject: Re: [PATCH 2/7] pinctrl: mediatek: paris: Fix
 PIN_CONFIG_BIAS_DISABLE readback

-----Original Message-----
From: Chen-Yu Tsai <wenst@...omium.org>
To: Sean Wang <sean.wang@...nel.org>, Linus Walleij <
linus.walleij@...aro.org>, Matthias Brugger <matthias.bgg@...il.com>
Cc: Chen-Yu Tsai <wenst@...omium.org>, 
linux-mediatek@...ts.infradead.org, linux-gpio@...r.kernel.org, 
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Zhiyong Tao <zhiyong.tao@...iatek.com>, Guodong Liu <
guodong.liu@...iatek.com>
Subject: [PATCH 2/7] pinctrl: mediatek: paris: Fix
PIN_CONFIG_BIAS_DISABLE readback
Date: Tue, 11 Jan 2022 19:22:39 +0800

When reading back pin bias settings, if the pin is not in a
bias-disabled state, the function should return -EINVAL.

Fix this in the mediatek-paris pinctrl library so that the read back
state is not littered with bogus a "input bias disabled" combined with
"pull up" or "pull down" states.

Fixes: 805250982bb5 ("pinctrl: mediatek: add pinctrl-paris that
implements the vendor dt-bindings")
Signed-off-by: Chen-Yu Tsai <wenst@...omium.org>
---
 drivers/pinctrl/mediatek/pinctrl-paris.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c
b/drivers/pinctrl/mediatek/pinctrl-paris.c
index f9f9110f2107..1ca598ea7ba7 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -97,8 +97,8 @@ static int mtk_pinconf_get(struct pinctrl_dev
*pctldev,
 			if (err)
 				goto out;
 			if (param == PIN_CONFIG_BIAS_DISABLE) {
-				if (ret == MTK_PUPD_SET_R1R0_00)
-					ret = MTK_DISABLE;
+				if (ret != MTK_PUPD_SET_R1R0_00)
+					err = -EINVAL;
Hi Chen-Yu

When tht API "hw->soc->bias_get_combo(hw, desc, &pullup, &ret)" is
called,
The ret vaule of may be MTK_DISABLE OR MTK_PUPD_SET_R1R0_00 or  (pullen
== 0),  All those cases are expected to be as "bias-disable".
We advices to keep original code,

+				if (ret == MTK_PUPD_SET_R1R0_00)
+	
				ret = MTK_DISABLE;
+				if (ret != MTK_DISABLE)
+					err = -EINVAL;

Thanks
 			} else if (param == PIN_CONFIG_BIAS_PULL_UP) {
 				/* When desire to get pull-up value,
return
 				 *  error if current setting is pull-
down