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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-11-28 08:27:36 +0300 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2018-12-07 12:38:28 +0300 |
| commit | a2a05c2f530c663f6f23cee1e57dc6d45a11a9e9 (patch) | |
| tree | 0b4764a99dbe13c500d06b49750e52882adc045f /drivers/mtd | |
| parent | 1b489effdb6dc16f63f254ee4c0d579929089e1d (diff) | |
| download | linux-a2a05c2f530c663f6f23cee1e57dc6d45a11a9e9.tar.xz | |
mtd: rawnand: denali: remove ->dev_ready() hook
The Denali NAND IP has no way to read out the current signal level
of the R/B# pin. Instead, denali_dev_ready() checks if the R/B#
transition has already happened. (The INTR__INT_ACT interrupt is
asserted at the rising edge of the R/B# pin.) It is not a correct
way to implement the ->dev_ready() hook.
In fact, it has a drawback; in the nand_scan_ident phase, the chip
detection iterates over maxchips until it fails to find a homogeneous
chip. For the last loop, nand_reset() fails if no chip is there.
If ->dev_ready hook exists, nand_command(_lp) calls nand_wait_ready()
after NAND_CMD_RESET. However, we know denali_dev_ready() never
returns 1 unless there exists a chip that toggles R/B# in that chip
select. Then, nand_wait_ready() just ends up with wasting 400 msec,
in the end, shows the "timeout while waiting for chip to become ready"
warning.
Let's remove the mis-implemented dev_ready hook, and fallback to
sending the NAND_CMD_STATUS and nand_wait_status_ready(), which
bails out more quickly.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/raw/denali.c | 23 |
1 files changed, 1 insertions, 22 deletions
diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c index bad3b8ad5e0a..3f8ee9245adb 100644 --- a/drivers/mtd/nand/raw/denali.c +++ b/drivers/mtd/nand/raw/denali.c @@ -204,18 +204,6 @@ static uint32_t denali_wait_for_irq(struct denali_nand_info *denali, return denali->irq_status; } -static uint32_t denali_check_irq(struct denali_nand_info *denali) -{ - unsigned long flags; - uint32_t irq_status; - - spin_lock_irqsave(&denali->irq_lock, flags); - irq_status = denali->irq_status; - spin_unlock_irqrestore(&denali->irq_lock, flags); - - return irq_status; -} - static void denali_read_buf(struct nand_chip *chip, uint8_t *buf, int len) { struct mtd_info *mtd = nand_to_mtd(chip); @@ -288,8 +276,7 @@ static void denali_cmd_ctrl(struct nand_chip *chip, int dat, unsigned int ctrl) return; /* - * Some commands are followed by chip->legacy.dev_ready or - * chip->legacy.waitfunc. + * Some commands are followed by chip->legacy.waitfunc. * irq_status must be cleared here to catch the R/B# interrupt later. */ if (ctrl & NAND_CTRL_CHANGE) @@ -298,13 +285,6 @@ static void denali_cmd_ctrl(struct nand_chip *chip, int dat, unsigned int ctrl) denali->host_write(denali, DENALI_BANK(denali) | type, dat); } -static int denali_dev_ready(struct nand_chip *chip) -{ - struct denali_nand_info *denali = mtd_to_denali(nand_to_mtd(chip)); - - return !!(denali_check_irq(denali) & INTR__INT_ACT); -} - static int denali_check_erased_page(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, unsigned long uncor_ecc_flags, @@ -1360,7 +1340,6 @@ int denali_init(struct denali_nand_info *denali) chip->legacy.read_byte = denali_read_byte; chip->legacy.write_byte = denali_write_byte; chip->legacy.cmd_ctrl = denali_cmd_ctrl; - chip->legacy.dev_ready = denali_dev_ready; chip->legacy.waitfunc = denali_waitfunc; if (features & FEATURES__INDEX_ADDR) { |