On Tue, Jun 30, 2015 at 4:47 PM, Mike Looijmans <mike.looijm...@topic.nl> wrote:
> Micron QUAD mode expects command, address and data on 4 lanes instead of just
> one for command (extended SPI mode). This requires the controller to be in a
> special mode, so check first if the controller could be in that mode. If a
> controller does not have the SPI_TX_QUAD mode set, this setting has no chance
> of being valid at all, so don't try to enable it then, and just keep using
> the extended SPI mode.
>
> Tested on a Zynq 7000 with a n25q256a flash chip, this failed to function
> because of the introduction of:
> "driver:mtd:spi-nor: Add quad I/O support for Micron spi nor"
> This commit sets QUAD mode for most Micron chips without asking the controller
> whether it's possible to do so, and without telling the controller that a
> different mode is required, so it couldn't work.
>
> Signed-off-by: Mike Looijmans <mike.looijm...@topic.nl>
> ---
> drivers/mtd/spi-nor/spi-nor.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index e8f6131..10ba94f 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1398,6 +1398,8 @@ static int set_quad_mode(struct spi_nor *nor, struct
> flash_info *info)
> }
> return status;
> case CFI_MFR_ST:
> + if (!(nor->spi->mode & SPI_TX_QUAD))
> + return 0;
Should we return 0 ?
> status = micron_quad_enable(nor);
> if (status) {
> dev_err(nor->dev, "Micron quad-read not enabled\n");
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
