From abfe5a01ef1e463cbafdae461b693db34e308c02 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sat, 20 Feb 2010 12:13:49 +0100 Subject: firewire: cdev: add more flexible cycle timer ioctl The system time from CLOCK_REALTIME is not monotonic, hence problematic for the main user of the FW_CDEV_IOC_GET_CYCLE_TIMER ioctl. This issue exists in its successor ABI, i.e. raw1394, too. http://subversion.ffado.org/ticket/242 We now offer an alternative ioctl which lets the caller choose between CLOCK_REALTIME, CLOCK_MONOTONIC, and CLOCK_MONOTONIC_RAW as source of the local time, very similar to the clock_gettime libc function. The format of the local time return value matches that of clock_gettime (seconds and nanoseconds, instead of a single microseconds value from the existing ioctl). Signed-off-by: Stefan Richter --- drivers/firewire/core-cdev.c | 38 ++++++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-) (limited to 'drivers/firewire') diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 3c1ac0933d2..a4aa477b9b2 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -1031,22 +1031,46 @@ static int ioctl_stop_iso(struct client *client, void *buffer) return fw_iso_context_stop(client->iso_context); } -static int ioctl_get_cycle_timer(struct client *client, void *buffer) +static int ioctl_get_cycle_timer2(struct client *client, void *buffer) { - struct fw_cdev_get_cycle_timer *request = buffer; + struct fw_cdev_get_cycle_timer2 *request = buffer; struct fw_card *card = client->device->card; - struct timeval tv; + struct timespec ts = {0, 0}; u32 cycle_time; + int ret = 0; local_irq_disable(); cycle_time = card->driver->get_cycle_time(card); - do_gettimeofday(&tv); + + switch (request->clk_id) { + case CLOCK_REALTIME: getnstimeofday(&ts); break; + case CLOCK_MONOTONIC: do_posix_clock_monotonic_gettime(&ts); break; + case CLOCK_MONOTONIC_RAW: getrawmonotonic(&ts); break; + default: + ret = -EINVAL; + } local_irq_enable(); - request->local_time = tv.tv_sec * 1000000ULL + tv.tv_usec; - request->cycle_timer = cycle_time; + request->tv_sec = ts.tv_sec; + request->tv_nsec = ts.tv_nsec; + request->cycle_timer = cycle_time; + + return ret; +} + +static int ioctl_get_cycle_timer(struct client *client, void *buffer) +{ + struct fw_cdev_get_cycle_timer *request = buffer; + struct fw_cdev_get_cycle_timer2 ct2; + + ct2.clk_id = CLOCK_REALTIME; + ioctl_get_cycle_timer2(client, &ct2); + + request->local_time = ct2.tv_sec * USEC_PER_SEC + + ct2.tv_nsec / NSEC_PER_USEC; + request->cycle_timer = ct2.cycle_timer; return 0; } @@ -1320,6 +1344,7 @@ static int (* const ioctl_handlers[])(struct client *client, void *buffer) = { ioctl_get_speed, ioctl_send_broadcast_request, ioctl_send_stream_packet, + ioctl_get_cycle_timer2, }; static int dispatch_ioctl(struct client *client, @@ -1341,6 +1366,7 @@ static int dispatch_ioctl(struct client *client, struct fw_cdev_get_cycle_timer _0c; struct fw_cdev_allocate_iso_resource _0d; struct fw_cdev_send_stream_packet _13; + struct fw_cdev_get_cycle_timer2 _14; })]; int ret; -- cgit v1.2.3