Using SDK 3.1.2 and the Macronix MX25Lxxxx series of flash, you may have noticed that write operation is very slow.
Bytes are in fact written one by one, with a lots of overhead on the SPI, here is how to speed it up:
spi_flash.c in sflash_write()
Line 163 change:
max_write_size = (unsigned int) 1; /* TODO: this should be 256, but that causes write errors */
To:
max_write_size = (unsigned int) 256;
and later, line 197 replace:
write_size = ( size > max_write_size )? max_write_size : size;
By:
if (device_address % max_write_size) {
/* Not on a page boundary, limit write within the page*/
unsigned int nbBytesLeftOnPage = max_write_size - (device_address % max_write_size);
write_size = (size > nbBytesLeftOnPage) ? nbBytesLeftOnPage : size;
} else {
/* Page boundary, write as many bytes as we can */
write_size = size > max_write_size ? max_write_size : size;
}
Message was edited by: Guillaume Brivet
Fix logic when write is not page-aligned
