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 <[email protected]>
---
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/[email protected]/
---
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
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 <[email protected]>
We are missing a fixes tag here.
Fixes: 888a623db5d0 ("pwm: mtk-disp: Implement atomic API .apply()")
with that:
Reviewed-by: Matthias Brugger <[email protected]>
> ---
> 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/[email protected]/
> ---
> 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;
On Mon, May 29, 2023 at 6:43 PM Matthias Brugger <[email protected]> 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 <[email protected]>
>
> We are missing a fixes tag here.
> Fixes: 888a623db5d0 ("pwm: mtk-disp: Implement atomic API .apply()")
>
>
> with that:
> Reviewed-by: Matthias Brugger <[email protected]>
Tested-by: Fei Shao <[email protected]>
>
> > ---
> > 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/[email protected]/
> > ---
> > 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;
>
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 <[email protected]>
Acked-by: Uwe Kleine-K?nig <[email protected]>
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |