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 <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 3c1ac09..a4aa477 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1031,22 +1031,46 @@
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 @@
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 @@
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;