mtd: rawnand: use longest matching pattern
Sometimes the exec_op parser does not choose the optimal pattern if
multiple patterns with optional elements are available. Since the stack
automatically splits operations in multiple exec_op calls, a non-optimal
pattern gets broken up into multiple calls. E.g. an OOB read using the
vf610 driver:
nand: executing subop:
nand: ->CMD [0x00]
nand: ->ADDR [5 cyc: 00 08 ea 94 02]
nand: ->CMD [0x30]
nand: ->WAITRDY [max 200000 ms]
nand: DATA_IN [64 B]
nand: executing subop:
nand: CMD [0x00]
nand: ADDR [5 cyc: 00 08 ea 94 02]
nand: CMD [0x30]
nand: WAITRDY [max 200000 ms]
nand: ->DATA_IN [64 B]
However, the vf610 driver has a pattern which can execute the complete
command in a single go...
This patch makes sure that the longest matching pattern is chosen
instead of the first (potentially only partial) match. With this
change the vf610 reads the OOB in a single exec_op call:
nand: executing subop:
nand: ->CMD [0x00]
nand: ->ADDR [5 cyc: 00 08 c0 1d 00]
nand: ->CMD [0x30]
nand: ->WAITRDY [max 200000 ms]
nand: ->DATA_IN [64 B]
Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
Tested-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
1 file changed