| Message ID | 20230531031001.7440-1-shuijing.li@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] pwm: mtk_disp: Fix the disable flow of disp_pwm | expand |
Il 31/05/23 05:10, Shuijing Li ha scritto: > 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> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
On 31/05/2023 05:10, Shuijing Li wrote: > 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. Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
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;
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> --- Changes in v3: Add Fixes per suggestion from the previous thread: https://lore.kernel.org/lkml/CAC=S1nhVrbaAh2u7rG-=-RubsxTZvMBRZO-t0NA8jG7M8187EA@mail.gmail.com/ 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@pengutronix.de/ --- drivers/pwm/pwm-mtk-disp.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)