Re: [PATCH v3] ACPI/IORT: Remove erroneous id_count check in iort_node_get_rmr_info()

From: Lorenzo Pieralisi <lpieralisi@kernel.org>
To: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Guanghui Feng <guanghuifeng@linux.alibaba.com>,
	guohanjun@huawei.com, sudeep.holla@arm.com, rafael@kernel.org,
	linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, baolin.wang@linux.alibaba.com,
	alikernel-developer@linux.alibaba.com
Subject: Re: [PATCH v3] ACPI/IORT: Remove erroneous id_count check in iort_node_get_rmr_info()
Date: Thu, 27 Jul 2023 17:08:20 +0200	[thread overview]
Message-ID: <ZMKIZMfmBMHG0IOz@lpieralisi> (raw)
In-Reply-To: <20230727150042.GC19940@willie-the-truck>

On Thu, Jul 27, 2023 at 04:00:43PM +0100, Will Deacon wrote:
> On Thu, Jul 27, 2023 at 04:17:49PM +0200, Lorenzo Pieralisi wrote:
> > On Thu, Jul 27, 2023 at 02:59:02PM +0100, Catalin Marinas wrote:
> > > On Thu, Jul 27, 2023 at 03:39:27PM +0200, Lorenzo Pieralisi wrote:
> > > > On Mon, Jul 17, 2023 at 07:33:45PM +0800, Guanghui Feng wrote:
> > > > > According to the ARM IORT specifications DEN 0049 issue E,
> > > > > the "Number of IDs" field in the ID mapping format reports
> > > > > the number of IDs in the mapping range minus one.
> > > > > 
> > > > > In iort_node_get_rmr_info(), we erroneously skip ID mappings
> > > > > whose "Number of IDs" equal to 0, resulting in valid mapping
> > > > > nodes with a single ID to map being skipped, which is wrong.
> > > > > 
> > > > > Fix iort_node_get_rmr_info() by removing the bogus id_count
> > > > > check.
> > > > > 
> > > > > Fixes: 491cf4a6735a ("ACPI/IORT: Add support to retrieve IORT RMR reserved regions")
> > > > > Signed-off-by: Guanghui Feng <guanghuifeng@linux.alibaba.com>
> > > > > ---
> > > > >  drivers/acpi/arm64/iort.c | 3 ---
> > > > >  1 file changed, 3 deletions(-)
> > > > 
> > > > Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
> > > > 
> > > > Catalin/Will,
> > > > 
> > > > can you pick this up please ?
> > > 
> > > Would you like it merged in 6.5 or 6.6 is fine?
> > 
> > It is definitely a fix - I don't think that's super urgent
> > though, bug has been there since v6.0 so the fix can probably
> > wait to trickle back from v6.6.
> 
> On the flip side, it's a fix, Hanjun has tested it and we have a few
> weeks in case we need to revert it.
> 
> So I'd be inclined to say Catalin should pick it up for 6.5, unless
> there's a good reason to wait?

No reason to wait - I just wanted to make clear it is not urgent,
if it is possible it makes sense for it to get into v6.5.

Thanks,
Lorenzo

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