FlapJackApps/libdivecomputer
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Increase the BLE packet size

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In the latest G2 firmware v2.0, the size of the BLE packets increased to
101 bytes (with a one byte header and 100 bytes of actual payload). This
caused the download to fail, because the internal buffer was suddenly
too small for those larger packets.

These larger packets are most likely due to an update in the BLE stack
of the dive computer. Originally, the maximum BLE packet size was just
20 bytes (excluding the 4 byte L2CAP header and 3 bytes GATT header),
but BLE 4.2 increased the maximum packet size to 244 bytes (or 251 bytes
with the headers).

The USB HID code path keeps using the same fixed size packets as before.
This commit is contained in:
Jef Driesen 2022-11-02 19:46:42 +01:00
parent 755f23fdfa
commit ed0b21beae
1 changed files with 12 additions and 5 deletions
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17
src/uwatec_smart.c
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@ -275,9 +275,13 @@ uwatec_smart_usbhid_send (uwatec_smart_device_t *device, unsigned char cmd, cons
{
dc_status_t rc = DC_STATUS_SUCCESS;
dc_device_t *abstract = (dc_device_t *) device;
unsigned char buf[PACKETSIZE_USBHID_TX + 1];
dc_transport_t transport = dc_iostream_get_transport(device->iostream);
unsigned char buf[DATASIZE + 3];
if (size + 3 > sizeof(buf)) {
size_t packetsize = transport == DC_TRANSPORT_USBHID ?
PACKETSIZE_USBHID_TX + 1 : sizeof(buf);
if (size > DATASIZE || size + 3 > packetsize) {
ERROR (abstract->context, "Command too large (" DC_PRINTF_SIZE ").", size);
return DC_STATUS_INVALIDARGS;
}
@ -295,7 +299,7 @@ uwatec_smart_usbhid_send (uwatec_smart_device_t *device, unsigned char cmd, cons
if (dc_iostream_get_transport(device->iostream) == DC_TRANSPORT_BLE) {
rc = dc_iostream_write(device->iostream, buf + 1, size + 2, NULL);
} else {
rc = dc_iostream_write(device->iostream, buf, sizeof(buf), NULL);
rc = dc_iostream_write(device->iostream, buf, packetsize, NULL);
}
if (rc != DC_STATUS_SUCCESS) {
ERROR (abstract->context, "Failed to send the command.");
@ -311,12 +315,15 @@ uwatec_smart_usbhid_receive (uwatec_smart_device_t *device, dc_event_progress_t
dc_status_t rc = DC_STATUS_SUCCESS;
dc_device_t *abstract = (dc_device_t *) device;
dc_transport_t transport = dc_iostream_get_transport(device->iostream);
unsigned char buf[PACKETSIZE_USBHID_RX];
unsigned char buf[DATASIZE + 1];
size_t packetsize = transport == DC_TRANSPORT_USBHID ?
PACKETSIZE_USBHID_RX : sizeof(buf);
size_t nbytes = 0;
while (nbytes < size) {
size_t transferred = 0;
rc = dc_iostream_read (device->iostream, buf, sizeof(buf), &transferred);
rc = dc_iostream_read (device->iostream, buf, packetsize, &transferred);
if (rc != DC_STATUS_SUCCESS) {
ERROR (abstract->context, "Failed to receive the packet.");
return rc;