pwm: mtk_disp: Fix the disable flow of disp_pwm

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>

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 79e321e..2401b67 100644 (file)
--- 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;