Re: [v4,7/7] thermal: mediatek: use spinlock to protect PTPCORESEL

From: Daniel Lezcano
Date: Fri May 22 2020 - 11:36:51 EST


On 23/03/2020 13:15, Michael Kao wrote:
> From: "michael.kao" <michael.kao@xxxxxxxxxxxx>
>
> The driver of thermal and svs will use the
> same register for the project which should select
> bank before reading sensor value.

Here there is a design problem AFAICT. The sensor should not be using
external locks.



> Signed-off-by: Michael Kao <michael.kao@xxxxxxxxxxxx>
> ---
> drivers/thermal/mtk_thermal.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> index 9eaca432920e..594ad4f0f8cd 100644
> --- a/drivers/thermal/mtk_thermal.c
> +++ b/drivers/thermal/mtk_thermal.c
> @@ -22,6 +22,7 @@
> #include <linux/thermal.h>
> #include <linux/reset.h>
> #include <linux/types.h>
> +#include <linux/power/mtk_svs.h>
>
> /* AUXADC Registers */
> #define AUXADC_CON1_SET_V 0x008
> @@ -262,7 +263,7 @@ struct mtk_thermal {
> struct clk *clk_peri_therm;
> struct clk *clk_auxadc;
> /* lock: for getting and putting banks */
> - struct mutex lock;
> + unsigned long flags;
>
> /* Calibration values */
> s32 adc_ge;
> @@ -561,7 +562,7 @@ static void mtk_thermal_get_bank(struct mtk_thermal_bank *bank)
> u32 val;
>
> if (mt->conf->need_switch_bank) {
> - mutex_lock(&mt->lock);
> + mt->flags = claim_mtk_svs_lock();
>
> val = readl(mt->thermal_base + PTPCORESEL);
> val &= ~0xf;
> @@ -581,7 +582,7 @@ static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
> struct mtk_thermal *mt = bank->mt;
>
> if (mt->conf->need_switch_bank)
> - mutex_unlock(&mt->lock);
> + release_mtk_svs_lock(mt->flags);
> }
>
> /**
> @@ -938,8 +939,6 @@ static int mtk_thermal_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - mutex_init(&mt->lock);
> -
> mt->dev = &pdev->dev;
>
> auxadc = of_parse_phandle(np, "mediatek,auxadc", 0);
>


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