From: Shuijing Li shuijing.li@mediatek.com
[ 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 --- 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 79e321e96f56a..2401b67332417 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;