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@xxxxxxxxxxxx>
Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Tested-by: Fei Shao <fshao@xxxxxxxxxxxx>
---
Changes in v3:
Add Fixes per suggestion from the previous thread:
https://lore.kernel.org/lkml/CAC=S1nhVrbaAh2u7rG-=-RubsxTZvMBRZO-t0NA8jG7M8187EA@xxxxxxxxxxxxxx/
Changes in v2:
Use
if (A && B) {
something();
}
instead of
if (A) {
if (B) {
something();
}
}
per suggestion from the previous thread:
https://lore.kernel.org/lkml/20230515140346.bxeu6xewi6a446nd@xxxxxxxxxxxxxx/
---
drivers/pwm/pwm-mtk-disp.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 79e321e96f56..2401b6733241 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;
--
2.40.1
