Hi Geert
Thanks for your remarks.
Today only write_reg could be call with len=0 (spi-nor.c:
write_enable/disable, set_4byte, erase_chip)
But your remark make sense to prevent: gcc warning and framework
evolution ...
-In stm32-quadspi.c transfer data is enabled if tx_data is true (some
actions under this bool)
stm32_qspi_write_reg has already this protection with "!!(buf && len > 0);"
but we could extend this protection
- cmd.tx_data = true;
+ cmd.tx_data = !!(len > 0);
In : stm32_qspi_read, stm32_qspi_write, stm32_qspi_read_reg
-And to avoid gcc warning: I prefer initialize "ret" in the beginning of
function
- int ret;
+ int ret = 0;
I tested this changes, and it's ok for me.
Geert could you resend a new version, or do you prefer that I take care
of it
BR
Ludo
On 07/15/2017 10:00 AM, Geert Uytterhoeven wrote:
With gcc 4.1.2:
drivers/mtd/spi-nor/stm32-quadspi.c: In function ‘stm32_qspi_tx_poll’:
drivers/mtd/spi-nor/stm32-quadspi.c:230: warning: ‘ret’ may be used
uninitialized in this function
Indeed, if stm32_qspi_cmd.len is zero, ret will be uninitialized.
This length is passed from outside the driver using the
spi_nor.{read,write}{,_reg}() callbacks.
Several functions in drivers/mtd/spi-nor/spi-nor.c (e.g. write_enable(),
write_disable(), and erase_chip()) call spi_nor.write_reg() with a zero
length.
Fix this by returning an explicit zero on success.
Fixes: 0d43d7ab277a048c ("mtd: spi-nor: add driver for STM32 quad spi flash
controller")
Signed-off-by: Geert Uytterhoeven <ge...@linux-m68k.org>
---
drivers/mtd/spi-nor/stm32-quadspi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/stm32-quadspi.c
b/drivers/mtd/spi-nor/stm32-quadspi.c
index 86c0931543c538c3..ad6a3e1844cbe5ec 100644
--- a/drivers/mtd/spi-nor/stm32-quadspi.c
+++ b/drivers/mtd/spi-nor/stm32-quadspi.c
@@ -240,12 +240,12 @@ static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
STM32_QSPI_FIFO_TIMEOUT_US);
if (ret) {
dev_err(qspi->dev, "fifo timeout (stat:%#x)\n", sr);
- break;
+ return ret;
}
tx_fifo(buf++, qspi->io_base + QUADSPI_DR);
}
- return ret;
+ return 0;
}
static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
