Hi Pauli,
On Sun, Apr 27, 2025 at 12:25 PM Pauli Virtanen <pav@xxxxxx> wrote:
>
> Add org.bluez.Media.SupportedFeatures. Add feature tx-timestamping.
> ---
>
> Notes:
> v3:
> - fix #includes
>
> v2:
> - use SIOCETHTOOL to get kernel support
>
> profiles/audio/media.c | 74 ++++++++++++++++++++++++++++++++++++++++++
> src/adapter.h | 3 ++
> 2 files changed, 77 insertions(+)
>
> diff --git a/profiles/audio/media.c b/profiles/audio/media.c
> index 69c6dc671..07264cfa1 100644
> --- a/profiles/audio/media.c
> +++ b/profiles/audio/media.c
> @@ -18,6 +18,17 @@
> #include <errno.h>
> #include <inttypes.h>
>
> +#include <time.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <linux/errqueue.h>
> +#include <linux/net_tstamp.h>
> +#include <linux/ethtool.h>
> +#include <linux/sockios.h>
> +#include <net/if.h>
> +#include <sys/socket.h>
> +#include <sys/ioctl.h>
> +
> #include <glib.h>
>
> #include "lib/bluetooth.h"
> @@ -81,6 +92,7 @@ struct media_adapter {
> #ifdef HAVE_AVRCP
> GSList *players; /* Players list */
> #endif
> + int so_timestamping;
> };
>
> struct endpoint_request {
> @@ -3340,8 +3352,69 @@ static gboolean supported_uuids(const GDBusPropertyTable *property,
> return TRUE;
> }
One thing that just occurred to me, can ETHTOOL_GET_TS_INFO be written
as well? If it can we could make this just an ioctl operation where we
attempt to enable so_timestamping field and then the kernel checks if
it can be enabled, that way we don't have to introduce another to
D-Bus since so_timestamping would only be enabled if bluetoothd had
enabled it, that said we need to confirm that would fail with older
kernels.
> +static bool probe_tx_timestamping(struct media_adapter *adapter)
> +{
> + struct ifreq ifr = {};
> + struct ethtool_ts_info cmd = {};
> + int sk = -1;
> +
> + if (adapter->so_timestamping != -1)
> + goto done;
> +
> + snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "hci%u",
> + btd_adapter_get_index(adapter->btd_adapter));
> + ifr.ifr_data = (void *)&cmd;
> + cmd.cmd = ETHTOOL_GET_TS_INFO;
> +
> + sk = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
> + if (sk < 0)
> + goto error;
> + if (ioctl(sk, SIOCETHTOOL, &ifr))
> + goto error;
> + close(sk);
> +
> + adapter->so_timestamping = cmd.so_timestamping;
> +
> +done:
> + return adapter->so_timestamping & SOF_TIMESTAMPING_TX_SOFTWARE;
> +
> +error:
> + if (sk >= 0)
> + close(sk);
> + adapter->so_timestamping = 0;
> + return false;
> +}
> +
> +static const struct {
> + const char *name;
> + bool (*probe)(struct media_adapter *adapter);
> +} features[] = {
> + { "tx-timestamping", probe_tx_timestamping },
> +};
> +
> +static gboolean supported_features(const GDBusPropertyTable *property,
> + DBusMessageIter *iter, void *data)
> +{
> + struct media_adapter *adapter = data;
> + DBusMessageIter entry;
> + size_t i;
> +
> + dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
> + DBUS_TYPE_STRING_AS_STRING, &entry);
> +
> + for (i = 0; i < ARRAY_SIZE(features); ++i)
> + if (features[i].probe(adapter))
> + dbus_message_iter_append_basic(&entry, DBUS_TYPE_STRING,
> + &features[i].name);
> +
> + dbus_message_iter_close_container(iter, &entry);
> +
> + return TRUE;
> +}
> +
> static const GDBusPropertyTable media_properties[] = {
> { "SupportedUUIDs", "as", supported_uuids },
> + { "SupportedFeatures", "as", supported_features },
> { }
> };
>
> @@ -3383,6 +3456,7 @@ int media_register(struct btd_adapter *btd_adapter)
> adapter = g_new0(struct media_adapter, 1);
> adapter->btd_adapter = btd_adapter_ref(btd_adapter);
> adapter->apps = queue_new();
> + adapter->so_timestamping = -1;
>
> if (!g_dbus_register_interface(btd_get_dbus_connection(),
> adapter_get_path(btd_adapter),
> diff --git a/src/adapter.h b/src/adapter.h
> index 6b2bc28f6..9371cdefb 100644
> --- a/src/adapter.h
> +++ b/src/adapter.h
> @@ -262,6 +262,9 @@ bool btd_le_connect_before_pairing(void);
>
> bool btd_adapter_has_settings(struct btd_adapter *adapter, uint32_t settings);
>
> +int btd_adapter_get_so_timestamping(struct btd_adapter *adapter, int proto,
> + int *so_timestamping);
> +
> enum experimental_features {
> EXP_FEAT_DEBUG = 1 << 0,
> EXP_FEAT_LE_SIMULT_ROLES = 1 << 1,
> --
> 2.49.0
>
>
--
Luiz Augusto von Dentz
