| Message ID | 20230518115258.14320-1-shuijing.li@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] pwm: mtk_disp: Fix the disable flow of disp_pwm | expand |
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;
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; >
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
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. 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(-)