]> git.kernelconcepts.de Git - karo-tx-linux.git/commit
mtd: nand: atmel: Relax tADL_min constraint
authorBoris Brezillon <boris.brezillon@free-electrons.com>
Wed, 23 Aug 2017 18:45:01 +0000 (20:45 +0200)
committerBrian Norris <computersforpeace@gmail.com>
Fri, 25 Aug 2017 03:59:50 +0000 (20:59 -0700)
commitbe3e83e3471cd0faff2c2d88fe9cfc73d9a9745a
tree7f95cf515d56da4b1f4aac1f60e782271d5e8472
parentb974696da1cfc5aa0c29ed97dc8f6c239899e64b
mtd: nand: atmel: Relax tADL_min constraint

Version 4 of the ONFI spec mandates that tADL be at least 400 nanoseconds,
but, depending on the master clock rate, 400 ns may not fit in the tADL
field of the SMC reg. We need to relax the check and accept the -ERANGE
return code.

Note that previous versions of the ONFI spec had a lower tADL_min (100 or
200 ns). It's not clear why this timing constraint got increased but it
seems most NANDs are fine with values lower than 400ns, so we should be
safe.

Fixes: f9ce2eddf176 ("mtd: nand: atmel: Add ->setup_data_interface() hooks")
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
drivers/mtd/nand/atmel/nand-controller.c