* [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm
@ 2023-05-31 3:10 Shuijing Li
2023-05-31 8:25 ` AngeloGioacchino Del Regno
2023-05-31 9:17 ` Alexandre Mergnat
0 siblings, 2 replies; 3+ messages in thread
From: Shuijing Li @ 2023-05-31 3:10 UTC (permalink / raw)
To: thierry.reding, u.kleine-koenig, matthias.bgg, angelogioacchino.delregno
Cc: devicetree, jitao.shi, linux-pwm, linux-kernel,
Project_Global_Chrome_Upstream_Group, Shuijing Li,
linux-mediatek, linux-arm-kernel
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(-)
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-31 3:10 [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
@ 2023-05-31 8:25 ` AngeloGioacchino Del Regno
2023-05-31 9:17 ` Alexandre Mergnat
1 sibling, 0 replies; 3+ messages in thread
From: AngeloGioacchino Del Regno @ 2023-05-31 8:25 UTC (permalink / raw)
To: Shuijing Li, thierry.reding, u.kleine-koenig, matthias.bgg
Cc: devicetree, jitao.shi, linux-pwm, linux-kernel,
Project_Global_Chrome_Upstream_Group, linux-mediatek,
linux-arm-kernel
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>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-31 3:10 [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
2023-05-31 8:25 ` AngeloGioacchino Del Regno
@ 2023-05-31 9:17 ` Alexandre Mergnat
1 sibling, 0 replies; 3+ messages in thread
From: Alexandre Mergnat @ 2023-05-31 9:17 UTC (permalink / raw)
To: Shuijing Li, thierry.reding, u.kleine-koenig, matthias.bgg,
angelogioacchino.delregno
Cc: devicetree, jitao.shi, linux-pwm, linux-kernel,
Project_Global_Chrome_Upstream_Group, linux-mediatek,
linux-arm-kernel
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>
--
Regards,
Alexandre
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-05-31 9:17 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-05-31 3:10 [PATCH v3] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
2023-05-31 8:25 ` AngeloGioacchino Del Regno
2023-05-31 9:17 ` Alexandre Mergnat
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).