This patch adds the FEATURE_WRSR_WREN bit to the feature_bits for many of the supported Eon chips. I was unable to find datasheets for all the similar Eon chips... there seems to be some huge number of variants listed on http://www.eonssi.com/products/products.aspx . Perhaps we can safely assume they are sanely uniform and apply FEATURE_WRSR_WREN to all of them?