Messages in this thread | | | From | Masahiro Yamada <> | Date | Tue, 26 Sep 2017 17:17:49 +0900 | Subject | Re: [PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID |
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2017-09-26 15:43 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>: > On Tue, 26 Sep 2017 12:39:24 +0900 > Masahiro Yamada <yamada.masahiro@socionext.com> wrote: > >> Read Status and Read ID require tWHR before reading the first data. >> Insert a very short wait to make sure to meet the spec. >> >> I have not seen any problem report for now, but nand_command() and >> nand_command_lP() are generic hooks, so it makes sense to implement >> fail-safe code here. >> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> >> --- >
OK, will do.
BTW, I see unconditional wait for tWB a few lines below, but it gives no performance regression because we will wait much longer in nand_wait_ready().
/* * Apply this short delay always to ensure that we do wait tWB in * any case on any machine. */ ndelay(100);
nand_wait_ready(mtd);
-- Best Regards Masahiro Yamada
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