Re: [PATCH v3 09/32] mtd: spi-nor: Pointer parameter for FSR in spi_nor_read_fsr()

Boris Brezillon
2019-10-31T10:53:59Z

On Tue, 29 Oct 2019 11:17:02 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> Let the callers pass the pointer to the DMA-able buffer where
> the value of the Flag Status Register will be written. This way we
> avoid the casts between int and u8, which can be confusing.
>
> Caller stops compare the return value of spi_nor_read_fsr() with negative,
> spi_nor_read_fsr() returns 0 on success and -errno otherwise.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> drivers/mtd/spi-nor/spi-nor.c | 38 ++++++++++++++++++++------------------
> 1 file changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index dc44d1206f77..0d38aede4de7 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -456,12 +456,15 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
> return ret;
> }
>
> -/*
> - * Read the flag status register, returning its value in the location
> - * Return the status register value.
> - * Returns negative if error occurred.
> +/**
> + * spi_nor_read_fsr() - Read the Flag Status Register.
> + * @nor: pointer to 'struct spi_nor'
> + * @fsr: pointer to a DMA-able buffer where the value of the
> + * Flag Status Register will be written.
> + *
> + * Return: 0 on success, -errno otherwise.
> */
> -static int spi_nor_read_fsr(struct spi_nor *nor)
> +static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
> {
> int ret;
>
> @@ -470,20 +473,18 @@ static int spi_nor_read_fsr(struct spi_nor *nor)
> SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDFSR, 1),
> SPI_MEM_OP_NO_ADDR,
> SPI_MEM_OP_NO_DUMMY,
> - SPI_MEM_OP_DATA_IN(1, nor->bouncebuf, 1));
> + SPI_MEM_OP_DATA_IN(1, fsr, 1));
>
> ret = spi_mem_exec_op(nor->spimem, &op);
> } else {
> ret = nor->controller_ops->read_reg(nor, SPINOR_OP_RDFSR,
> - nor->bouncebuf, 1);
> + fsr, 1);
> }
>
> - if (ret) {
> + if (ret)
> dev_err(nor->dev, "error %d reading FSR\n", ret);
> - return ret;
> - }
>
> - return nor->bouncebuf[0];
> + return ret;
> }
>
> /*
> @@ -705,17 +706,18 @@ static int spi_nor_clear_fsr(struct spi_nor *nor)
>
> static int spi_nor_fsr_ready(struct spi_nor *nor)
> {
> - int fsr = spi_nor_read_fsr(nor);
> - if (fsr < 0)
> - return fsr;
> + int ret = spi_nor_read_fsr(nor, &nor->bouncebuf[0]);

Didn't comment on the previous patch, but why not simply pass
nor->bouncebuf here?

Anyway, that's just a detail.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> +
> + if (ret)
> + return ret;
>
> - if (fsr & (FSR_E_ERR | FSR_P_ERR)) {
> - if (fsr & FSR_E_ERR)
> + if (nor->bouncebuf[0] & (FSR_E_ERR | FSR_P_ERR)) {
> + if (nor->bouncebuf[0] & FSR_E_ERR)
> dev_err(nor->dev, "Erase operation failed.\n");
> else
> dev_err(nor->dev, "Program operation failed.\n");
>
> - if (fsr & FSR_PT_ERR)
> + if (nor->bouncebuf[0] & FSR_PT_ERR)
> dev_err(nor->dev,
> "Attempted to modify a protected sector.\n");
>
> @@ -723,7 +725,7 @@ static int spi_nor_fsr_ready(struct spi_nor *nor)
> return -EIO;
> }
>
> - return fsr & FSR_READY;
> + return nor->bouncebuf[0] & FSR_READY;
> }
>
> static int spi_nor_ready(struct spi_nor *nor)