diff options
| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2020-01-30 00:55:54 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2020-02-01 01:14:32 +0900 |
| commit | 21d4a3ca549b5b1b8243c845b15f91142bfa3528 (patch) | |
| tree | 33fcf210705da30c228dafe1ad442f2e2883fbde /drivers/mtd/nand/raw | |
| parent | 9925df051a7964e939298fe54df60153409b6352 (diff) | |
mtd: rawnand: denali_dt: insert udelay() after reset deassert
When the reset signal is de-asserted, the HW-controlled bootstrap
starts running unless it is disabled in the SoC integration.
It issues some commands to detect a NAND chip, and sets up registers
automatically. Until this process finishes, software should avoid
any register access.
Without this delay function, some of UniPhier boards hangs up while
executing nand_scan_ident(). (denali_read_byte() is blocked)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'drivers/mtd/nand/raw')
| -rw-r--r-- | drivers/mtd/nand/raw/denali_dt.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/mtd/nand/raw/denali_dt.c b/drivers/mtd/nand/raw/denali_dt.c index 91d0f20aae..1afc61f876 100644 --- a/drivers/mtd/nand/raw/denali_dt.c +++ b/drivers/mtd/nand/raw/denali_dt.c @@ -136,11 +136,19 @@ static int denali_dt_probe(struct udevice *dev) } ret = reset_get_bulk(dev, &resets); - if (ret) + if (ret) { dev_warn(dev, "Can't get reset: %d\n", ret); - else + } else { reset_deassert_bulk(&resets); + /* + * When the reset is deasserted, the initialization sequence is + * kicked (bootstrap process). The driver must wait until it is + * finished. Otherwise, it will result in unpredictable behavior. + */ + udelay(200); + } + return denali_init(denali); } |