From: Bastien Curutchet Date: Wed, 8 Jan 2025 15:30:12 +0000 (+0100) Subject: pps: clients: gpio: Bypass edge's direction check when not needed X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a01f6287c244f35eeec11ca932d09061181eed8c;p=users%2Fjedix%2Flinux-maple.git pps: clients: gpio: Bypass edge's direction check when not needed In the IRQ handler, the GPIO's state is read to verify the direction of the edge that triggered the interruption before generating the PPS event. If a pulse is too short, the GPIO line can reach back its original state before this verification and the PPS event is lost. This check is needed when info->capture_clear is set because it needs interruptions on both rising and falling edges. When info->capture_clear is not set, interruption is triggered by one edge only so this check can be omitted. Add a warning if irq_handler is left without triggering any PPS event. Bypass the edge's direction verification when info->capture_clear is not set. Signed-off-by: Bastien Curutchet Acked-by: Rodolfo Giometti Link: https://lore.kernel.org/r/20250108153012.514925-1-bastien.curutchet@bootlin.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index f77b19884f051..75c1bae30a7cb 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -52,7 +52,9 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) info = data; - rising_edge = gpiod_get_value(info->gpio_pin); + /* Small trick to bypass the check on edge's direction when capture_clear is unset */ + rising_edge = info->capture_clear ? + gpiod_get_value(info->gpio_pin) : !info->assert_falling_edge; if ((rising_edge && !info->assert_falling_edge) || (!rising_edge && info->assert_falling_edge)) pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data); @@ -60,6 +62,8 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) ((rising_edge && info->assert_falling_edge) || (!rising_edge && !info->assert_falling_edge))) pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data); + else + dev_warn_ratelimited(&info->pps->dev, "IRQ did not trigger any PPS event\n"); return IRQ_HANDLED; }