* [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm
@ 2023-05-18 11:52 Shuijing Li
2023-05-29 10:43 ` Matthias Brugger
2023-06-14 9:01 ` Uwe Kleine-König
0 siblings, 2 replies; 4+ messages in thread
From: Shuijing Li @ 2023-05-18 11:52 UTC (permalink / raw)
To: thierry.reding, u.kleine-koenig, matthias.bgg, angelogioacchino.delregno
Cc: devicetree, linux-pwm, linux-kernel, linux-arm-kernel,
linux-mediatek, Project_Global_Chrome_Upstream_Group, jitao.shi,
Shuijing Li
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.
Signed-off-by: Shuijing Li <shuijing.li@mediatek.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] 4+ messages in thread
* Re: [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-18 11:52 [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
@ 2023-05-29 10:43 ` Matthias Brugger
2023-05-30 8:28 ` Fei Shao
2023-06-14 9:01 ` Uwe Kleine-König
1 sibling, 1 reply; 4+ messages in thread
From: Matthias Brugger @ 2023-05-29 10:43 UTC (permalink / raw)
To: Shuijing Li, thierry.reding, u.kleine-koenig, angelogioacchino.delregno
Cc: devicetree, linux-pwm, linux-kernel, linux-arm-kernel,
linux-mediatek, Project_Global_Chrome_Upstream_Group, jitao.shi
On 18/05/2023 13:52, 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.
>
> Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
We are missing a fixes tag here.
Fixes: 888a623db5d0 ("pwm: mtk-disp: Implement atomic API .apply()")
with that:
Reviewed-by: Matthias Brugger <matthias.bgg@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;
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-29 10:43 ` Matthias Brugger
@ 2023-05-30 8:28 ` Fei Shao
0 siblings, 0 replies; 4+ messages in thread
From: Fei Shao @ 2023-05-30 8:28 UTC (permalink / raw)
To: Matthias Brugger
Cc: Shuijing Li, thierry.reding, u.kleine-koenig,
angelogioacchino.delregno, devicetree, linux-pwm, linux-kernel,
linux-arm-kernel, linux-mediatek,
Project_Global_Chrome_Upstream_Group, jitao.shi
On Mon, May 29, 2023 at 6:43 PM Matthias Brugger <matthias.bgg@gmail.com> wrote:
>
>
>
> On 18/05/2023 13:52, 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.
> >
> > Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
>
> We are missing a fixes tag here.
> Fixes: 888a623db5d0 ("pwm: mtk-disp: Implement atomic API .apply()")
>
>
> with that:
> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Tested-by: Fei Shao <fshao@chromium.org>
>
> > ---
> > 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;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-18 11:52 [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
2023-05-29 10:43 ` Matthias Brugger
@ 2023-06-14 9:01 ` Uwe Kleine-König
1 sibling, 0 replies; 4+ messages in thread
From: Uwe Kleine-König @ 2023-06-14 9:01 UTC (permalink / raw)
To: Shuijing Li
Cc: thierry.reding, matthias.bgg, angelogioacchino.delregno,
devicetree, linux-pwm, linux-kernel, linux-arm-kernel,
linux-mediatek, Project_Global_Chrome_Upstream_Group, jitao.shi
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On Thu, May 18, 2023 at 07:52:58PM +0800, 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.
>
> Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-kleine@pengutronix.de>
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-05-18 11:52 [PATCH v2] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
2023-05-29 10:43 ` Matthias Brugger
2023-05-30 8:28 ` Fei Shao
2023-06-14 9:01 ` Uwe Kleine-König
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