Date: Mon, 9 Dec 2019 19:00:39 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r355565 - head/sys/dev/gpio Message-ID: <201912091900.xB9J0dOM008651@repo.freebsd.org>
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Author: ian Date: Mon Dec 9 19:00:39 2019 New Revision: 355565 URL: https://svnweb.freebsd.org/changeset/base/355565 Log: Switch gpioths(4) from using a callout to a taskqueue for periodic polling of the sensor hardware. Part of the polling process involves signalling the chip then waiting 20 milliseconds. This was being done with DELAY(), which is a pretty rude thing to do in a callout. Now a taskqueue_thread task is scheduled to do the polling, and because sleeping is allowed in the task context, pause_sbt() replaces DELAY() for the 20ms wait. Modified: head/sys/dev/gpio/gpioths.c Modified: head/sys/dev/gpio/gpioths.c ============================================================================== --- head/sys/dev/gpio/gpioths.c Mon Dec 9 17:58:22 2019 (r355564) +++ head/sys/dev/gpio/gpioths.c Mon Dec 9 19:00:39 2019 (r355565) @@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$"); #include <sys/errno.h> #include <sys/systm.h> #include <sys/sysctl.h> +#include <sys/taskqueue.h> #include <dev/gpio/gpiobusvar.h> @@ -90,7 +91,8 @@ struct gpioths_softc { int temp; int hum; int fails; - struct callout callout; + struct timeout_task task; + bool detaching; }; static int @@ -148,7 +150,7 @@ gpioths_dht_initread(struct gpioths_softc *sc) */ gpio_pin_setflags(sc->pin, GPIO_PIN_OUTPUT); gpio_pin_set_active(sc->pin, false); - DELAY(GPIOTHS_DHT_STARTCYCLE); + pause_sbt("gpioths", ustosbt(GPIOTHS_DHT_STARTCYCLE), C_PREL(2), 0); gpio_pin_set_active(sc->pin, true); gpio_pin_setflags(sc->pin, GPIO_PIN_INPUT); } @@ -285,14 +287,16 @@ error: } static void -gpioths_poll(void *arg) +gpioths_poll(void *arg, int pending __unused) { struct gpioths_softc *sc; sc = (struct gpioths_softc *)arg; gpioths_dht_readbytes(sc); - callout_schedule(&sc->callout, GPIOTHS_POLLTIME * hz); + if (!sc->detaching) + taskqueue_enqueue_timeout_sbt(taskqueue_thread, &sc->task, + GPIOTHS_POLLTIME * SBT_1S, 0, C_PREL(3)); } static int @@ -309,6 +313,8 @@ gpioths_attach(device_t dev) sc->dev = dev; + TIMEOUT_TASK_INIT(taskqueue_thread, &sc->task, 0, gpioths_poll, sc); + #ifdef FDT /* Try to configure our pin from fdt data on fdt-based systems. */ err = gpio_pin_get_by_ofw_idx(dev, ofw_bus_get_node(dev), PIN_IDX, @@ -355,9 +361,11 @@ gpioths_attach(device_t dev) /* * Do an initial read so we have correct values for reporting before - * registering the sysctls that can access those values. + * registering the sysctls that can access those values. This also + * schedules the periodic polling the driver does every few seconds to + * update the sysctl variables. */ - gpioths_dht_readbytes(sc); + gpioths_poll(sc, 0); sysctl_add_oid(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "temperature", \ CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE, @@ -370,9 +378,6 @@ gpioths_attach(device_t dev) CTLFLAG_RD, &sc->fails, 0, "failures since last successful read"); - callout_init(&sc->callout, 1); - callout_reset(&sc->callout, GPIOTHS_POLLTIME * hz, gpioths_poll, sc); - return (0); } @@ -383,7 +388,9 @@ gpioths_detach(device_t dev) sc = device_get_softc(dev); gpio_pin_release(sc->pin); - callout_drain(&sc->callout); + sc->detaching = true; + while (taskqueue_cancel_timeout(taskqueue_thread, &sc->task, NULL) != 0) + taskqueue_drain_timeout(taskqueue_thread, &sc->task); return (0); }
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