On 02/03/2018 07:37 AM, Mark Cave-Ayland wrote:
> Use the direction registers as a mask to ensure that only input pins are
> updated upon write.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
> hw/misc/macio/cuda.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
> index 23b7e0f5b0..7214e7adcb 100644
> --- a/hw/misc/macio/cuda.c
> +++ b/hw/misc/macio/cuda.c
> @@ -359,11 +359,11 @@ static void cuda_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
>
> switch(addr) {
> case CUDA_REG_B:
> - s->b = val;
> + s->b = (s->b & ~s->dirb) | (val & s->dirb);
I personally find it easier to read in 2 lines (&=~, |=)
It might be useful to log invalid guest values:
if (val & ~s->dirb) {
GUEST_ERROR();
val &= s->dirb;
}
s->b |= val;
> cuda_update(s);
> break;
> case CUDA_REG_A:
> - s->a = val;
> + s->a = (s->a & ~s->dira) | (val & s->dira);
Ditto.
Regardless:
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> break;
> case CUDA_REG_DIRB:
> s->dirb = val;
>