2019-07-29 17:04:37

by Avi Fishman

Subject: [PATCH] [v4] clocksource/drivers/npcm: fix GENMASK and timer operation

NPCM7XX_Tx_OPER GENMASK bits where wrong,
Since NPCM7XX_REG_TICR0 register reset value of those bits was 0,
it did not cause an issue.
in npcm7xx_timer_oneshot() the original NPCM7XX_REG_TCSR0 register was
read again after masking it with ~NPCM7XX_Tx_OPER so the masking didn't
take effect.

npcm7xx_timer_periodic() was not wrong but it wrote to NPCM7XX_REG_TICR0
in a middle of read modify write to NPCM7XX_REG_TCSR0 which is
confusing.
npcm7xx_timer_oneshot() did wrong calculation

Signed-off-by: Avi Fishman <[email protected]>
---
drivers/clocksource/timer-npcm7xx.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/timer-npcm7xx.c
b/drivers/clocksource/timer-npcm7xx.c
index 8a30da7f083b..9780ffd8010e 100644
--- a/drivers/clocksource/timer-npcm7xx.c
+++ b/drivers/clocksource/timer-npcm7xx.c
@@ -32,7 +32,7 @@
#define NPCM7XX_Tx_INTEN BIT(29)
#define NPCM7XX_Tx_COUNTEN BIT(30)
#define NPCM7XX_Tx_ONESHOT 0x0
-#define NPCM7XX_Tx_OPER GENMASK(27, 3)
+#define NPCM7XX_Tx_OPER GENMASK(28, 27)
#define NPCM7XX_Tx_MIN_PRESCALE 0x1
#define NPCM7XX_Tx_TDR_MASK_BITS 24
#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
@@ -84,8 +84,6 @@ static int npcm7xx_timer_oneshot(struct
clock_event_device *evt)

val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val &= ~NPCM7XX_Tx_OPER;
-
- val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val |= NPCM7XX_START_ONESHOT_Tx;
writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);

@@ -97,12 +95,11 @@ static int npcm7xx_timer_periodic(struct
clock_event_device *evt)
struct timer_of *to = to_timer_of(evt);
u32 val;

+ writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
+
val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val &= ~NPCM7XX_Tx_OPER;
-
- writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
val |= NPCM7XX_START_PERIODIC_Tx;
-
writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);

return 0;
--
2.18.0

2019-07-29 17:06:16

by Avi Fishman

Subject: Re: [PATCH] [v4] clocksource/drivers/npcm: fix GENMASK and timer operation

Please discard this. my mail tool corruppted it again.

On Mon, Jul 29, 2019 at 7:50 PM Avi Fishman <[email protected]> wrote:
>
> NPCM7XX_Tx_OPER GENMASK bits where wrong,
> Since NPCM7XX_REG_TICR0 register reset value of those bits was 0,
> it did not cause an issue.
> in npcm7xx_timer_oneshot() the original NPCM7XX_REG_TCSR0 register was
> read again after masking it with ~NPCM7XX_Tx_OPER so the masking didn't
> take effect.
>
> npcm7xx_timer_periodic() was not wrong but it wrote to NPCM7XX_REG_TICR0
> in a middle of read modify write to NPCM7XX_REG_TCSR0 which is
> confusing.
> npcm7xx_timer_oneshot() did wrong calculation
>
> Signed-off-by: Avi Fishman <[email protected]>
> ---
> drivers/clocksource/timer-npcm7xx.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clocksource/timer-npcm7xx.c
> b/drivers/clocksource/timer-npcm7xx.c
> index 8a30da7f083b..9780ffd8010e 100644
> --- a/drivers/clocksource/timer-npcm7xx.c
> +++ b/drivers/clocksource/timer-npcm7xx.c
> @@ -32,7 +32,7 @@
> #define NPCM7XX_Tx_INTEN BIT(29)
> #define NPCM7XX_Tx_COUNTEN BIT(30)
> #define NPCM7XX_Tx_ONESHOT 0x0
> -#define NPCM7XX_Tx_OPER GENMASK(27, 3)
> +#define NPCM7XX_Tx_OPER GENMASK(28, 27)
> #define NPCM7XX_Tx_MIN_PRESCALE 0x1
> #define NPCM7XX_Tx_TDR_MASK_BITS 24
> #define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
> @@ -84,8 +84,6 @@ static int npcm7xx_timer_oneshot(struct
> clock_event_device *evt)
>
> val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
> val &= ~NPCM7XX_Tx_OPER;
> -
> - val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
> val |= NPCM7XX_START_ONESHOT_Tx;
> writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
>
> @@ -97,12 +95,11 @@ static int npcm7xx_timer_periodic(struct
> clock_event_device *evt)
> struct timer_of *to = to_timer_of(evt);
> u32 val;
>
> + writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
> +
> val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
> val &= ~NPCM7XX_Tx_OPER;
> -
> - writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
> val |= NPCM7XX_START_PERIODIC_Tx;
> -
> writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
>
> return 0;
> --
> 2.18.0



--
Regards,
Avi