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From: John Garry <john.garry@huawei.com>
To: Jiahui Cen <cenjiahui@huawei.com>, <linux-kernel@vger.kernel.org>
Cc: Wei Xu <xuwei5@hisilicon.com>, Arnd Bergmann <arnd@arndb.de>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	<xieyingtai@huawei.com>
Subject: Re: [PATCH] lib/logic_pio: Fix overlap check for pio registery
Date: Fri, 18 Dec 2020 10:40:13 +0000	[thread overview]
Message-ID: <2cde14cd-91da-aae4-70aa-656d629259e6@huawei.com> (raw)
In-Reply-To: <20201218062335.5320-1-cenjiahui@huawei.com>

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@huawei.com>
> ---
>   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

  reply	other threads:[~2020-12-18 10:41 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-18  6:23 [PATCH] lib/logic_pio: Fix overlap check for pio registery Jiahui Cen
2020-12-18 10:40 ` John Garry [this message]
2020-12-21  3:24   ` Jiahui Cen
2020-12-21 11:12     ` John Garry
2020-12-21 13:04       ` Jiahui Cen
2021-01-15 10:10         ` John Garry
2021-01-18  1:27           ` Jiahui Cen
2021-03-15 10:30             ` John Garry

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