sdkconfig.defaults: use standard defaults

[dhalbert]

• Fixes CP 10 has 4 stream sockets; CP 9 had 8 #10606

Remove some lower-valued LWIP settings in sdkconfig.defaults on espressif. In particular, removed:

CONFIG_LWIP_MAX_ACTIVE_TCP=4
CONFIG_LWIP_MAX_LISTENING_TCP=4

These settings restricted the number of usable sockets. It looks like LWIP might have started paying more attention to these when it was updated in in ESP-IDF 5.4.1.

These were all removed:

CONFIG_LWIP_MAX_ACTIVE_TCP=4
CONFIG_LWIP_MAX_LISTENING_TCP=4
CONFIG_LWIP_TCP_SYNMAXRTX=6
CONFIG_LWIP_TCP_SND_BUF_DEFAULT=2880
CONFIG_LWIP_TCP_WND_DEFAULT=2880
CONFIG_LWIP_TCP_RTO_TIME=3000

Reading Kconfig, it appears the defaults were reasonable, and we might get better performance using the defaults (which are computed in some cases).

Thanks @anecdata for the issue and for the clue re the CONFIG_LWIP_MAX... settings.

[jbrelwof]

@dhalbert were you able to reproduce the initial problem and then verify that this fixed it? If not, I could probably build & test this on a Lolin S2 or S3 mini

[dhalbert]

Yes, I reproduced the problem easily with the test program in #10606, and verified this fixes it.

[anecdata]

Tested with the minimal example, and with an async example with 2-3 servers and the remainder of the sockets as clients, and all of the connections get made. Thanks, Dan!

[tannewt]

Thank you!