Comment 475 for bug 1734147

#474

If you have status register 2 bit 6 set. e.g it reads 0x40 or something like that, you can just clear that bit and the chip becomes read/write.

For more information about the status register you can find if you find "w25q64dw" datasheet (or whatever the serial flash chip you have there). Those explain all the details (typically there's a chapter "Status Registers" or similar). I've used this link:

http://svod.od.ua/files/W25Q64DW.pdf

Page 15 shows the both status registers.