[PATCH u-boot-spi v3 05/10] mtd: spi-flash: Check for zero length in legacy spi_flash_*()

Marek Behún
2021-10-05T13:57:37Z

Check for zero length in the legacy spi_flash_read() /
spi_flash_write() / spi_flash_erase() functions.
On zero length, return 0 immediately, don't call the underlying method.

Rationale:
- these legacy functions call the _read(), _write() and _erase() methods
of struct mtd
- the DM callers of these methods already check for zero length
- making all callers of these methods check for zero length makes it
possible to remove the check from implementations of these _read(),
_write() and _erase() methods

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
include/spi_flash.h | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/include/spi_flash.h b/include/spi_flash.h
index 3d747c925b..4d4ae89c19 100644
--- a/include/spi_flash.h
+++ b/include/spi_flash.h
@@ -165,6 +165,9 @@ static inline int spi_flash_read(struct spi_flash *flash, u32 offset,
struct mtd_info *mtd = &flash->mtd;
size_t retlen;

+ if (!len)
+ return 0;
+
return mtd->_read(mtd, offset, len, &retlen, buf);
}

@@ -174,6 +177,9 @@ static inline int spi_flash_write(struct spi_flash *flash, u32 offset,
struct mtd_info *mtd = &flash->mtd;
size_t retlen;

+ if (!len)
+ return 0;
+
return mtd->_write(mtd, offset, len, &retlen, buf);
}

@@ -188,6 +194,9 @@ static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
return -EINVAL;
}

+ if (!len)
+ return 0;
+
memset(&instr, 0, sizeof(instr));
instr.addr = offset;
instr.len = len;
--
2.32.0