2022-08-29 04:37:58

by Xinlei Lee (李昕磊)

[permalink] [raw]
Subject: [PATCH] pwm: mtk-disp: Fix the parameters calculated by the enabled flag of disp_pwm.

From: xinlei lee <[email protected]>

In the original mtk_disp_pwm_get_state() function, the result of reading
con0 & BIT(0) is enabled as disp_pwm.
In order to conform to the register table, we should use the disp_pwm
base address as the enabled judgment.

Fixes: 3f2b16734914 ("pwm: mtk-disp: Implement atomic API .get_state()")

Signed-off-by: xinlei lee <[email protected]>
Reviewed-by: Miles Chen <[email protected]>
---
Base on the branch of Linux-next/master.
Split from series [1].
[1] https://patchwork.kernel.org/project/linux-mediatek/cover/[email protected]/
---
---
drivers/pwm/pwm-mtk-disp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index c605013..50425cd 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -197,7 +197,7 @@ static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
rate = clk_get_rate(mdp->clk_main);
con0 = readl(mdp->base + mdp->data->con0);
con1 = readl(mdp->base + mdp->data->con1);
- state->enabled = !!(con0 & BIT(0));
+ state->enabled = !!(readl(mdp->base) & BIT(0));
clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
period = FIELD_GET(PWM_PERIOD_MASK, con1);
/*
--
2.6.4


Subject: Re: [PATCH] pwm: mtk-disp: Fix the parameters calculated by the enabled flag of disp_pwm.

Il 29/08/22 06:04, [email protected] ha scritto:
> From: xinlei lee <[email protected]>
>
> In the original mtk_disp_pwm_get_state() function, the result of reading
> con0 & BIT(0) is enabled as disp_pwm.
> In order to conform to the register table, we should use the disp_pwm
> base address as the enabled judgment.
>
> Fixes: 3f2b16734914 ("pwm: mtk-disp: Implement atomic API .get_state()")
>
> Signed-off-by: xinlei lee <[email protected]>
> Reviewed-by: Miles Chen <[email protected]>

This fix is valid for all MediaTek SoCs that are currently supported in
pwm-mtk-disp (and some others that aren't supported yet).

Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

2022-09-13 09:29:39

by Uwe Kleine-König

[permalink] [raw]
Subject: Re: [PATCH] pwm: mtk-disp: Fix the parameters calculated by the enabled flag of disp_pwm.

Hello,

On Mon, Aug 29, 2022 at 12:04:12PM +0800, [email protected] wrote:
> From: xinlei lee <[email protected]>
>
> In the original mtk_disp_pwm_get_state() function, the result of reading
> con0 & BIT(0) is enabled as disp_pwm.
> In order to conform to the register table, we should use the disp_pwm
> base address as the enabled judgment.

Do you want to say:

The enable bit of the hardware is bit 0 of the DISP_PWM_EN
register at offset 0 for all supported hardwares. Up to now the
bit was wrongly assumed to be in the CON0 register.

?

> Fixes: 3f2b16734914 ("pwm: mtk-disp: Implement atomic API .get_state()")
>

This newline is unusal.

> Signed-off-by: xinlei lee <[email protected]>
> Reviewed-by: Miles Chen <[email protected]>
> ---
> Base on the branch of Linux-next/master.
> Split from series [1].
> [1] https://patchwork.kernel.org/project/linux-mediatek/cover/[email protected]/
> ---
> ---
> drivers/pwm/pwm-mtk-disp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> index c605013..50425cd 100644
> --- a/drivers/pwm/pwm-mtk-disp.c
> +++ b/drivers/pwm/pwm-mtk-disp.c
> @@ -197,7 +197,7 @@ static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
> rate = clk_get_rate(mdp->clk_main);
> con0 = readl(mdp->base + mdp->data->con0);
> con1 = readl(mdp->base + mdp->data->con1);
> - state->enabled = !!(con0 & BIT(0));
> + state->enabled = !!(readl(mdp->base) & BIT(0));

I would expect this to better be:

state->enabled = !!(readl(mdp->base + DISP_PWM_EN) & BIT(0));

which is the same for the compiler but a bit more descriptive for the
human reader.

> clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
> period = FIELD_GET(PWM_PERIOD_MASK, con1);
> /*

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |


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