Re: [PATCH] lib/logic_pio: Fix overlap check for pio registery

[John Garry]

On 18/12/2020 06:23, Jiahui Cen wrote:
> Since the [start, end) is a half-open interval, a range with the end equal
> to the start of another range should not be considered as overlapped.
>
> Signed-off-by: Jiahui Cen <cenjiahui@xxxxxxxxxx>
> ---
>   lib/logic_pio.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/logic_pio.c b/lib/logic_pio.c
> index f32fe481b492..445d611f1dc1 100644
> --- a/lib/logic_pio.c
> +++ b/lib/logic_pio.c
> @@ -57,7 +57,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
>   		    new_range->flags == LOGIC_PIO_CPU_MMIO) {
>   			/* for MMIO ranges we need to check for overlap */
>   			if (start >= range->hw_start + range->size ||
> -			    end < range->hw_start) {
> +			    end <= range->hw_start) {

It looks like your change is correct, but should not really have an 
impact in practice since:
a: BIOSes generally list ascending IO port CPU addresses
b. there is space between IO port CPU address regions

Have you seen a problem here?

Thanks,
John