- lwipopts.h contains settings you can tweak the performance of lwIP
- Before enabling lwIP, the AVR32's lwIP example will change the CPU clock from 12Mhz to 48Mhz, thus all serial communication baud rate, which is also used by print_dbg, goes up.
- Like 2), if SDRAM is used in the project, sdram_init(48000000) should be called after enabling lwIP
- To increase output bandwidth, increase the number of TCP_SND_BUF
- To increase input bandwidth, increase the number of TCP_WND
- To increase input buffer size, increase PBUF_POOL_SIZE and PBUF_POOL_BUFSIZE.
- Watch out for the product of PBUF_POOL_SIZE and PBUF_POOL_BUFSIZE and TCP_SND_BUF, when they add up close to 64K, be aware of memory problem!
- Due to an internal bug in lwIP, do not send a lot of small packets to lwIP continuously, pack them into a bigger packet, or the unblocking lwip_recv will end up blocking and lost sync totally.
- Backing up the entire project directory is NOT enough to preserve the configuration of a project. If a project is trashed and you need to bring back the backed up directory, use import to bring the backup directory back. Unfortunately, the framework will no longer recognize the project
- Unfortunately, lwip_send doesn't report the
err code from its lower layer netconn_send, which can
be:
#define ERR_OK 0 /* No error, everything OK. */
#define ERR_MEM -1 /* Out of memory error. */
#define ERR_BUF -2 /* Buffer error. */
#define ERR_RTE -3 /* Routing problem. */
#define ERR_ABRT -4 /* Connection aborted. */
#define ERR_RST -5 /* Connection reset. */
#define ERR_CLSD -6 /* Connection closed. */
#define ERR_CONN -7 /* Not connected. */
#define ERR_VAL -8 /* Illegal value. */
#define ERR_ARG -9 /* Illegal argument. */
#define ERR_USE -10 /* Address in use. */
#define ERR_IF -11 /* Low-level netif error */
#define ERR_ISCONN -12 /* Already connected. */
#define ERR_TIMEOUT -13 /* Timeout. */
#define ERR_INPROGRESS -14 /* Operation in progress */
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Last update: 04/08/10