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Groups > linux.kernel > #1739491
| From | Masahiro Yamada <yamada.masahiro@socionext.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID |
| Date | 2017-09-26 05:50 +0200 |
| Message-ID | <utP2F-7zs-7@gated-at.bofh.it> (permalink) |
| Organization | linux.* mail to news gateway |
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> --- drivers/mtd/nand/nand_base.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index b1cf32c..55c0ba5 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -742,9 +742,12 @@ static void nand_command(struct mtd_info *mtd, unsigned int command, case NAND_CMD_ERASE1: case NAND_CMD_ERASE2: case NAND_CMD_SEQIN: + case NAND_CMD_SET_FEATURES: + return; + case NAND_CMD_STATUS: case NAND_CMD_READID: - case NAND_CMD_SET_FEATURES: + ndelay(200); /* tWHR */ return; case NAND_CMD_RESET: @@ -871,9 +874,12 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, case NAND_CMD_ERASE1: case NAND_CMD_ERASE2: case NAND_CMD_SEQIN: + case NAND_CMD_SET_FEATURES: + return; + case NAND_CMD_STATUS: case NAND_CMD_READID: - case NAND_CMD_SET_FEATURES: + ndelay(200); /* tWHR */ return; case NAND_CMD_RNDIN: -- 2.7.4
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[PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-26 05:50 +0200
Re: [PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-09-26 08:50 +0200
Re: [PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-26 10:20 +0200
Re: [PATCH] mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-09-26 10:30 +0200
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