[U-Boot] [PATCH 2/2] dm: spi: Check cs number before accessing slaves

[Jagan Teki]

On Thu, Aug 29, 2019 at 7:40 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> In spi_get_bus_and_cs() only bus number is checked before accessing
> slaves. We should check cs number as well.
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
>  drivers/spi/spi-uclass.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
> index 24de0b5..f633eb5 100644
> --- a/drivers/spi/spi-uclass.c
> +++ b/drivers/spi/spi-uclass.c
> @@ -271,6 +271,7 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
>  {
>         struct udevice *bus, *dev;
>         struct dm_spi_slave_platdata *plat;
> +       struct spi_cs_info info;
>         bool created = false;
>         int ret;
>
> @@ -283,6 +284,11 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
>                 printf("Invalid bus %d (err=%d)\n", busnum, ret);
>                 return ret;
>         }
> +       ret = spi_cs_info(bus, cs, &info);
> +       if (ret) {
> +               printf("Invalid cs %d (err=%d)\n", cs, ret);
> +               return ret;
> +       }
>         ret = spi_find_chip_select(bus, cs, &dev);

I think it would rather check the cs_info in spi_find_chip_select
function itself, make more sense.