According to datasheet both Dual and Quad Read is supported. The read test
shows x3.8 speed gain.
Does it have SFDP? Try adding PARSE_SFDP instead of the
NO_SFDP_FLAGS.
Some issues with its SFDP were known:
https://patchwork.ozlabs.org/project/linux-mtd/patch/1492068234-9509-1-git-send-email-dev@xxxxxxxxx/
Please post an SFDP dump of this flash [1].
^^^^^^^^^^^^^^^^xxd -p /sys/bus/spi/devices/spi0.0/sfdp53464450060102ff00060110300000ffc2000104100100ff84000102c000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