[PATCH] pwm: pwm-meson: fix handling of period/duty if greater than UINT_MAX

* [PATCH] pwm: pwm-meson: fix handling of period/duty if greater than UINT_MAX
@ 2023-05-03 19:58 Heiner Kallweit
  2023-05-03 20:24 ` Uwe Kleine-König
  2023-05-08 19:46 ` Martin Blumenstingl
  0 siblings, 2 replies; 6+ messages in thread
From: Heiner Kallweit @ 2023-05-03 19:58 UTC (permalink / raw)
  To: Jerome Brunet, Martin Blumenstingl, Neil Armstrong, Kevin Hilman,
	Uwe Kleine-König, thierry.reding
  Cc: linux-arm-kernel, open list:ARM/Amlogic Meson..., linux-pwm

state->period/duty are of type u64, and if their value is greater than
UINT_MAX, then the cast to uint will cause problems. Fix this by
changing the type of the respective local variables to u64.

Fixes: b79c3670e120 ("pwm: meson: Don't duplicate the polarity internally")
Cc: stable@vger.kernel.org
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/pwm/pwm-meson.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 3865538dd..33107204a 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -156,8 +156,9 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
 			  const struct pwm_state *state)
 {
 	struct meson_pwm_channel *channel = &meson->channels[pwm->hwpwm];
-	unsigned int duty, period, pre_div, cnt, duty_cnt;
+	unsigned int pre_div, cnt, duty_cnt;
 	unsigned long fin_freq;
+	u64 duty, period;
 
 	duty = state->duty_cycle;
 	period = state->period;
@@ -179,19 +180,19 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
 
 	dev_dbg(meson->chip.dev, "fin_freq: %lu Hz\n", fin_freq);
 
-	pre_div = div64_u64(fin_freq * (u64)period, NSEC_PER_SEC * 0xffffLL);
+	pre_div = div64_u64(fin_freq * period, NSEC_PER_SEC * 0xffffLL);
 	if (pre_div > MISC_CLK_DIV_MASK) {
 		dev_err(meson->chip.dev, "unable to get period pre_div\n");
 		return -EINVAL;
 	}
 
-	cnt = div64_u64(fin_freq * (u64)period, NSEC_PER_SEC * (pre_div + 1));
+	cnt = div64_u64(fin_freq * period, NSEC_PER_SEC * (pre_div + 1));
 	if (cnt > 0xffff) {
 		dev_err(meson->chip.dev, "unable to get period cnt\n");
 		return -EINVAL;
 	}
 
-	dev_dbg(meson->chip.dev, "period=%u pre_div=%u cnt=%u\n", period,
+	dev_dbg(meson->chip.dev, "period=%llu pre_div=%u cnt=%u\n", period,
 		pre_div, cnt);
 
 	if (duty == period) {
@@ -204,14 +205,13 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
 		channel->lo = cnt;
 	} else {
 		/* Then check is we can have the duty with the same pre_div */
-		duty_cnt = div64_u64(fin_freq * (u64)duty,
-				     NSEC_PER_SEC * (pre_div + 1));
+		duty_cnt = div64_u64(fin_freq * duty, NSEC_PER_SEC * (pre_div + 1));
 		if (duty_cnt > 0xffff) {
 			dev_err(meson->chip.dev, "unable to get duty cycle\n");
 			return -EINVAL;
 		}
 
-		dev_dbg(meson->chip.dev, "duty=%u pre_div=%u duty_cnt=%u\n",
+		dev_dbg(meson->chip.dev, "duty=%llu pre_div=%u duty_cnt=%u\n",
 			duty, pre_div, duty_cnt);
 
 		channel->pre_div = pre_div;
-- 
2.40.1


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