5.4-stable review patch. If anyone has any objections, please let me know.
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From: Uwe Kleine-König u.kleine-koenig@baylibre.com
[ Upstream commit 928446a5302eee30ebb32075c0db5dda5a138fb7 ]
Considering that the driver doesn't enable the used clocks (and also that clk_get_rate() returns 0 if CONFIG_HAVE_CLK is unset) better check the return value of clk_get_rate() for being non-zero before dividing by it.
Fixes: 3479bbd1e1f8 ("pwm: fsl-ftm: More relaxed permissions for updating period") Signed-off-by: Uwe Kleine-König u.kleine-koenig@baylibre.com Link: https://lore.kernel.org/r/b68351a51017035651bc62ad3146afcb706874f0.174350168... Signed-off-by: Uwe Kleine-König ukleinek@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pwm/pwm-fsl-ftm.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c index 59272a9204793..8221f286f5828 100644 --- a/drivers/pwm/pwm-fsl-ftm.c +++ b/drivers/pwm/pwm-fsl-ftm.c @@ -123,6 +123,9 @@ static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc, unsigned long long exval;
rate = clk_get_rate(fpc->clk[fpc->period.clk_select]); + if (rate >> fpc->period.clk_ps == 0) + return 0; + exval = ticks; exval *= 1000000000UL; do_div(exval, rate >> fpc->period.clk_ps); @@ -195,6 +198,9 @@ static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc, unsigned int period = fpc->period.mod_period + 1; unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
+ if (!period_ns) + return 0; + duty = (unsigned long long)duty_ns * period; do_div(duty, period_ns);