From: Nylon Chen <nylon.chen@sifive.com>
To: linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org,
conor@kernel.org, robh+dt@kernel.org,
krzysztof.kozlowski+dt@linaro.org, palmer@dabbelt.com,
paul.walmsley@sifive.com, aou@eecs.berkeley.edu,
thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de
Cc: vincent.chen@sifive.com, zong.li@sifve.com,
nylon.chen@sifive.com, nylon7717@gmail.com
Subject: [PATCH v7 3/3] pwm: sifive: Fix the error in the idempotent test within the pwm_apply_state_debug function
Date: Tue, 23 Jan 2024 14:17:48 +0800 [thread overview]
Message-ID: <20240123061748.8844-4-nylon.chen@sifive.com> (raw)
In-Reply-To: <20240123061748.8844-1-nylon.chen@sifive.com>
Round the result to the nearest whole number. This ensures that
real_period is always a reasonable integer that is not lower than the
actual value.
e.g.
$ echo 110 > /sys/devices/platform/led-controller-1/leds/d12/brightness
$ .apply is not idempotent (ena=1 pol=0 1739692/4032985) -> (ena=1 pol=0 1739630/4032985)
Co-developed-by: Zong Li <zong.li@sifve.com>
Signed-off-by: Zong Li <zong.li@sifve.com>
Signed-off-by: Nylon Chen <nylon.chen@sifive.com>
---
drivers/pwm/pwm-sifive.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
index b07c8598bb21..7cf7a76cdb44 100644
--- a/drivers/pwm/pwm-sifive.c
+++ b/drivers/pwm/pwm-sifive.c
@@ -101,7 +101,7 @@ static void pwm_sifive_update_clock(struct pwm_sifive_ddata *ddata,
/* As scale <= 15 the shift operation cannot overflow. */
num = (unsigned long long)NSEC_PER_SEC << (PWM_SIFIVE_CMPWIDTH + scale);
- ddata->real_period = div64_ul(num, rate);
+ ddata->real_period = DIV_ROUND_UP_ULL(num, rate);
dev_dbg(ddata->chip.dev,
"New real_period = %u ns\n", ddata->real_period);
}
--
2.42.0
prev parent reply other threads:[~2024-01-23 6:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-23 6:17 [PATCH v7 0/3] Change PWM-controlled LED pin active mode and algorithm Nylon Chen
2024-01-23 6:17 ` [PATCH v7 1/3] riscv: dts: sifive: unleashed/unmatched: Remove PWM controlled LED's active-low properties Nylon Chen
2024-01-23 6:17 ` [PATCH v7 2/3] pwm: sifive: change the PWM controlled LED algorithm Nylon Chen
2024-01-23 6:17 ` Nylon Chen [this message]
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