diff --git a/src/hardware/baylibre-acme/api.c b/src/hardware/baylibre-acme/api.c index 75f2c044..6ec4d749 100644 --- a/src/hardware/baylibre-acme/api.c +++ b/src/hardware/baylibre-acme/api.c @@ -18,6 +18,8 @@ */ #include "protocol.h" +#include +#include SR_PRIV struct sr_dev_driver baylibre_acme_driver_info; @@ -349,6 +351,10 @@ static int dev_acquisition_open(const struct sr_dev_inst *sdi) static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data) { struct dev_context *devc; + struct itimerspec tspec = { + .it_interval = { 0, 0 }, + .it_value = { 0, 0 } + }; (void)cb_data; @@ -360,19 +366,30 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data) devc = sdi->priv; devc->samples_read = 0; - - if (pipe(devc->pipe_fds)) { - sr_err("Error setting up pipe"); + devc->samples_missed = 0; + devc->timer_fd = timerfd_create(CLOCK_MONOTONIC, 0); + if (devc->timer_fd < 0) { + sr_err("Error creating timer fd"); return SR_ERR; } - devc->channel = g_io_channel_unix_new(devc->pipe_fds[0]); + tspec.it_interval.tv_sec = 0; + tspec.it_interval.tv_nsec = (1000000000L / devc->samplerate); + tspec.it_value = tspec.it_interval; + + if (timerfd_settime(devc->timer_fd, 0, &tspec, NULL)) { + sr_err("Failed to set timer"); + close(devc->timer_fd); + return SR_ERR; + } + + devc->channel = g_io_channel_unix_new(devc->timer_fd); g_io_channel_set_flags(devc->channel, G_IO_FLAG_NONBLOCK, NULL); g_io_channel_set_encoding(devc->channel, NULL, NULL); g_io_channel_set_buffered(devc->channel, FALSE); sr_session_source_add_channel(sdi->session, devc->channel, - G_IO_IN | G_IO_ERR, 1, bl_acme_receive_data, (void *)sdi); + G_IO_IN | G_IO_ERR, 1000, bl_acme_receive_data, (void *)sdi); /* Send header packet to the session bus. */ std_session_send_df_header(sdi, LOG_PREFIX); @@ -398,11 +415,15 @@ static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data) g_io_channel_shutdown(devc->channel, FALSE, NULL); g_io_channel_unref(devc->channel); devc->channel = NULL; + close(devc->timer_fd); /* Send last packet. */ packet.type = SR_DF_END; sr_session_send(sdi, &packet); + if (devc->samples_missed > 0) + sr_warn("%d samples missed", devc->samples_missed); + return SR_OK; } diff --git a/src/hardware/baylibre-acme/protocol.c b/src/hardware/baylibre-acme/protocol.c index dfd634bb..5552ff56 100644 --- a/src/hardware/baylibre-acme/protocol.c +++ b/src/hardware/baylibre-acme/protocol.c @@ -560,8 +560,8 @@ SR_PRIV void bl_acme_close_channel(struct sr_channel *ch) SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data) { - uint32_t cur_time, elapsed_time, diff_time; - int64_t time_to_sleep; + uint32_t cur_time, elapsed_time; + uint64_t nrexpiration; struct sr_datafeed_packet packet, framep; struct sr_datafeed_analog analog; struct sr_dev_inst *sdi; @@ -586,17 +586,18 @@ SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data) memset(&analog, 0, sizeof(struct sr_datafeed_analog)); analog.data = &valf; - /* - * Reading from sysfs takes some time - try to keep up with samplerate. - */ - if (devc->samples_read) { - cur_time = g_get_monotonic_time(); - diff_time = cur_time - devc->last_sample_fin; - time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time; - if (time_to_sleep > 0) - g_usleep(time_to_sleep); + if (read(devc->timer_fd, &nrexpiration, sizeof(nrexpiration)) < 0) { + sr_warn("Failed to read timer information"); + return TRUE; } + /* + * We were not able to process the previous timer expiration, we are + * overloaded. + */ + if (nrexpiration > 1) + devc->samples_missed += nrexpiration - 1; + framep.type = SR_DF_FRAME_BEGIN; sr_session_send(cb_data, &framep); diff --git a/src/hardware/baylibre-acme/protocol.h b/src/hardware/baylibre-acme/protocol.h index 4600211b..a3f4452c 100644 --- a/src/hardware/baylibre-acme/protocol.h +++ b/src/hardware/baylibre-acme/protocol.h @@ -65,9 +65,10 @@ struct dev_context { uint32_t num_channels; uint64_t samples_read; + uint64_t samples_missed; int64_t start_time; int64_t last_sample_fin; - int pipe_fds[2]; + int timer_fd; GIOChannel *channel; };