[PATCH linux dev-4.7] drivers/fsi: Add more time between clocking and data sampling

[Andrew Geissler]

On Wed, Mar 15, 2017 at 4:25 PM, Christopher Bostic
<cbostic at linux.vnet.ibm.com> wrote:
> Under high work loads the ARM core can occasionaly hit invalid
> timings between the FSI clock and data lines which leads to
> data crc errors.  Add further delay between clock switch and
> data line changes.
>
> Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
> ---
>  drivers/fsi/fsi-master-gpio.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
> index a8976d5..a93453f 100644
> --- a/drivers/fsi/fsi-master-gpio.c
> +++ b/drivers/fsi/fsi-master-gpio.c
> @@ -13,7 +13,7 @@
>
>  #include "fsi-master.h"
>
> -#define        FSI_GPIO_STD_DLY        1       /* Standard pin delay in nS */
> +#define        FSI_GPIO_STD_DLY        1       /* Standard pin delay in uS */
>  #define        FSI_ECHO_DELAY_CLOCKS   16      /* Number clocks for echo delay */
>  #define        FSI_PRE_BREAK_CLOCKS    50      /* Number clocks to prep for break */
>  #define        FSI_BREAK_CLOCKS        256     /* Number of clocks to issue break */
> @@ -86,9 +86,9 @@ static void clock_toggle(struct fsi_master_gpio *master, int count)
>         int i;
>
>         for (i = 0; i < count; i++) {
> -               ndelay(FSI_GPIO_STD_DLY);
> +               udelay(FSI_GPIO_STD_DLY);
>                 gpiod_set_value(master->gpio_clk, 0);
> -               ndelay(FSI_GPIO_STD_DLY);
> +               udelay(FSI_GPIO_STD_DLY);
>                 gpiod_set_value(master->gpio_clk, 1);
>         }
>  }
> @@ -97,7 +97,7 @@ static int sda_in(struct fsi_master_gpio *master)
>  {
>         int in;
>
> -       ndelay(FSI_GPIO_STD_DLY);
> +       udelay(FSI_GPIO_STD_DLY);
>         in = gpiod_get_value(master->gpio_data);
>         return in ? 1 : 0;
>  }
> --
> 1.8.2.2
>

Acked-by: Andrew Geissler <geissonator at gmail.com>