From: Johannes Berg <johannes@sipsolutions.net>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>, bhelgaas@google.com
Cc: Guenter Roeck <linux@roeck-us.net>,
"open list:PCI SUBSYSTEM" <linux-pci@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] PCI: Reinstate "PCI: Coalesce host bridge contiguous apertures"
Date: Wed, 17 Nov 2021 15:12:17 +0100 [thread overview]
Message-ID: <5331e942ff28bb191d62bb403b03ceb7d750856c.camel@sipsolutions.net> (raw)
In-Reply-To: <20210713125007.1260304-1-kai.heng.feng@canonical.com>
Hi!
So this patch landed now ... :)
> + /* Coalesce contiguous windows */
> + resource_list_for_each_entry_safe(window, n, &resources) {
> + if (list_is_last(&window->node, &resources))
> + break;
> +
> + next = list_next_entry(window, node);
> + offset = window->offset;
> + res = window->res;
> + next_offset = next->offset;
> + next_res = next->res;
> +
> + if (res->flags != next_res->flags || offset != next_offset)
> + continue;
> +
> + if (res->end + 1 == next_res->start) {
> + next_res->start = res->start;
> + res->flags = res->start = res->end = 0;
> + }
> + }
>
Maybe this was already a problem before - but I had a stupid thing in
arch/um/drivers/virt-pci.c (busn_resource has start == end == 0), and
your changes here caused that resource to be dropped off the list.
Now this wouldn't be a problem, but we add it using pci_add_resource()
and then that does a memory allocation, but you don't free it here? I'm
not sure it'd even be safe to free it here and I'll just set
busn_resource to have end==1 instead (it's all kind of virtual).
But I still wanted to ask if this might be a problem here for others.
johannes
next prev parent reply other threads:[~2021-11-17 14:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 7:57 [PATCH 1/1] PCI: Coalesce host bridge contiguous apertures without sorting Kai-Heng Feng
2021-07-13 8:45 ` Guenter Roeck
2021-07-13 8:49 ` Kai-Heng Feng
2021-07-13 9:06 ` Guenter Roeck
2021-07-13 12:50 ` [PATCH v2] PCI: Reinstate "PCI: Coalesce host bridge contiguous apertures" Kai-Heng Feng
2021-09-29 21:25 ` Bjorn Helgaas
2021-11-17 14:12 ` Johannes Berg [this message]
2022-07-13 9:36 ` Geert Uytterhoeven
2021-08-09 4:24 ` [PATCH] PCI/portdrv: Disallow runtime suspend when waekup is required but PME service isn't supported Kai-Heng Feng
2021-08-09 9:47 ` Lukas Wunner
2021-08-09 10:40 ` Kai-Heng Feng
2021-08-09 15:00 ` Lukas Wunner
2021-08-10 15:37 ` Kai-Heng Feng
2021-08-10 16:21 ` Lukas Wunner
2021-08-11 5:06 ` Kai-Heng Feng
2021-08-11 7:11 ` Lukas Wunner
2021-08-12 5:20 ` Kai-Heng Feng
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