[U-Boot] [PATCH v2 01/11] spi-mem: Claim SPI bus before spi mem access

[Jagan Teki]

On Fri, Dec 21, 2018 at 12:08 PM Vignesh R <vigneshr at ti.com> wrote:
>
> It is necessary to call spi_claim_bus() before starting any SPI
> transactions and this restriction would also apply when calling spi-mem
> operationss. Therefore claim and release bus before requesting transfer
> via exec_op.
>
> Signed-off-by: Vignesh R <vigneshr at ti.com>
> ---
>  drivers/spi/spi-mem.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> index 1da20b8de5c4..4c1463118ab2 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -231,7 +231,13 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
>                 mutex_lock(&ctlr->bus_lock_mutex);
>                 mutex_lock(&ctlr->io_mutex);
>  #endif
> +               ret = spi_claim_bus(slave);
> +               if (ret < 0)
> +                       return ret;
> +
>                 ret = ops->mem_ops->exec_op(slave, op);
> +
> +               spi_release_bus(slave);

This making spi claims twice, since it's been doing before spi_xfer in
below code. better to make it before the if.