From: Shuijing Li <shuijing.li@mediatek.com>
Date: Wed, 31 May 2023 03:10:01 +0000 (+0800)
Subject: pwm: mtk_disp: Fix the disable flow of disp_pwm
X-Git-Tag: v6.1.39~130
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=07e81c9208d9a3d51402ed981427d805c324a2a6;p=platform%2Fkernel%2Flinux-starfive.git

pwm: mtk_disp: Fix the disable flow of disp_pwm

[ Upstream commit bc13d60e4e1e945b34769a4a4c2b172e8552abe5 ]

There is a flow error in the original mtk_disp_pwm_apply() function.
If this function is called when the clock is disabled, there will be a
chance to operate the disp_pwm register, resulting in disp_pwm exception.
Fix this accordingly.

Fixes: 888a623db5d0 ("pwm: mtk-disp: Implement atomic API .apply()")
Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Tested-by: Fei Shao <fshao@chromium.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 3811578..db28628 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -79,14 +79,11 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (state->polarity != PWM_POLARITY_NORMAL)
 		return -EINVAL;
 
-	if (!state->enabled) {
-		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
-					 0x0);
-
-		if (mdp->enabled) {
-			clk_disable_unprepare(mdp->clk_mm);
-			clk_disable_unprepare(mdp->clk_main);
-		}
+	if (!state->enabled && mdp->enabled) {
+		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
+					 mdp->data->enable_mask, 0x0);
+		clk_disable_unprepare(mdp->clk_mm);
+		clk_disable_unprepare(mdp->clk_main);
 
 		mdp->enabled = false;
 		return 0;