drivers: wifi: esp: rely on +IPD after each +CIPRECVDATA
Dump of communication between ESP chip and Zephyr shows that
+IPD:<sock>,<bytes_avail> is always received after +CIPRECVDATA. This
means that we don't need to update sock->bytes_avail in esp_workq
thread. Additionally there is no need to schedule next AT+CIPRECVDATA
request, as that will be done by +IPD handler anyway.
Relying on +IPD to be received after each +CIPRECVDATA (as long as there
is some more data to be received) allows to simplify operations on
sock->bytes_avail. From now on only esp_rx thread will update its value
and schedule AT+CIPRECVDATA in esp_workq thread. Then in
sock->bytes_avail will be treated as "readonly" in esp_workq
thread. This allows to prevent race condition when both esp_rx and
esp_workq threads could potentially update value of sock->bytes_avail
value at the same time.
<sock>,CLOSED message is received always after retrieving all data from
ESP chip (using AT+CIPRECVDATA), so there is no need to check whether
there are more bytes to be received before marking socket as closed in
Zephyr driver.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
1 file changed
