From: Javier Martinez Canillas <javier@osg.samsung.com>
To: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: linux-kernel@vger.kernel.org, Kukjin Kim <kgene@kernel.org>,
Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
linux-samsung-soc@vger.kernel.org,
Kyungmin Park <kyungmin.park@samsung.com>,
Krzysztof Kozlowski <k.kozlowski@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH 2/2] [media] exynos4-is: FIMC port parse should fail if there's no endpoint
Date: Tue, 22 Mar 2016 17:19:37 -0300 [thread overview]
Message-ID: <56F1A8D9.2000909@osg.samsung.com> (raw)
In-Reply-To: <56E2C206.6020103@samsung.com>
Hello Sylwester,
On 03/11/2016 10:03 AM, Sylwester Nawrocki wrote:
> On 03/04/2016 09:20 PM, Javier Martinez Canillas wrote:
>> The fimc_md_parse_port_node() function return 0 if an endpoint node is
>> not found but according to Documentation/devicetree/bindings/graph.txt,
>> a port must always have at least one enpoint.
>>
>> So return an -EINVAL errno code to the caller instead, so it knows that
>> the port node parse failed due an invalid Device Tree description.
>
> I don't think it is forbidden to have a port node in device tree
> containing no endpoint nodes. Empty port node means only that,
> for example, a subsystem has a port/bus for connecting external
> devices but nothing is actually connected to it.
>
> In case of Exynos CSIS it might not be so useful to have an empty
> port node specified in some top level *.dtsi file and only
> the endpoints specified in a board specific dts file. Nevertheless,
> I wouldn't be saying in general a port node must always have some
> endpoint node defined.
>
You are right, I asked Laurent and he confirms what you said that
it's possible to have ports with no endpoints. I still think the
DT binding docs could be more clear but that's a separate issue.
> I could apply this patch as it doesn't do any harm considering
> existing dts files in the kernel tree (arch/arm/boot/dts/
> exynos4412-trats2.dts), but the commit description would need to
> be changed.
>
No worries, the current code is correct if endpoints are optional
and this patch is wrong so it should not be applied.
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
WARNING: multiple messages have this Message-ID (diff)
From: javier@osg.samsung.com (Javier Martinez Canillas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] [media] exynos4-is: FIMC port parse should fail if there's no endpoint
Date: Tue, 22 Mar 2016 17:19:37 -0300 [thread overview]
Message-ID: <56F1A8D9.2000909@osg.samsung.com> (raw)
In-Reply-To: <56E2C206.6020103@samsung.com>
Hello Sylwester,
On 03/11/2016 10:03 AM, Sylwester Nawrocki wrote:
> On 03/04/2016 09:20 PM, Javier Martinez Canillas wrote:
>> The fimc_md_parse_port_node() function return 0 if an endpoint node is
>> not found but according to Documentation/devicetree/bindings/graph.txt,
>> a port must always have at least one enpoint.
>>
>> So return an -EINVAL errno code to the caller instead, so it knows that
>> the port node parse failed due an invalid Device Tree description.
>
> I don't think it is forbidden to have a port node in device tree
> containing no endpoint nodes. Empty port node means only that,
> for example, a subsystem has a port/bus for connecting external
> devices but nothing is actually connected to it.
>
> In case of Exynos CSIS it might not be so useful to have an empty
> port node specified in some top level *.dtsi file and only
> the endpoints specified in a board specific dts file. Nevertheless,
> I wouldn't be saying in general a port node must always have some
> endpoint node defined.
>
You are right, I asked Laurent and he confirms what you said that
it's possible to have ports with no endpoints. I still think the
DT binding docs could be more clear but that's a separate issue.
> I could apply this patch as it doesn't do any harm considering
> existing dts files in the kernel tree (arch/arm/boot/dts/
> exynos4412-trats2.dts), but the commit description would need to
> be changed.
>
No worries, the current code is correct if endpoints are optional
and this patch is wrong so it should not be applied.
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
next prev parent reply other threads:[~2016-03-22 20:19 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-04 20:20 [PATCH 0/2] [media] exynos4-is: Trivial fixes for DT port/endpoint parse logic Javier Martinez Canillas
2016-03-04 20:20 ` Javier Martinez Canillas
2016-03-04 20:20 ` [PATCH 1/2] [media] exynos4-is: Put node before s5pcsis_parse_dt() return error Javier Martinez Canillas
2016-03-04 20:20 ` Javier Martinez Canillas
2016-03-04 20:20 ` [PATCH 2/2] [media] exynos4-is: FIMC port parse should fail if there's no endpoint Javier Martinez Canillas
2016-03-04 20:20 ` Javier Martinez Canillas
2016-03-11 13:03 ` Sylwester Nawrocki
2016-03-11 13:03 ` Sylwester Nawrocki
2016-03-11 14:55 ` Javier Martinez Canillas
2016-03-11 14:55 ` Javier Martinez Canillas
2016-03-11 14:55 ` Javier Martinez Canillas
2016-03-22 20:19 ` Javier Martinez Canillas [this message]
2016-03-22 20:19 ` Javier Martinez Canillas
2016-03-05 4:35 ` [PATCH 0/2] [media] exynos4-is: Trivial fixes for DT port/endpoint parse logic Krzysztof Kozlowski
2016-03-05 4:35 ` Krzysztof Kozlowski
2016-03-07 9:24 ` Sylwester Nawrocki
2016-03-07 9:24 ` Sylwester Nawrocki
2016-03-07 9:24 ` Sylwester Nawrocki
2016-03-07 14:30 ` Javier Martinez Canillas
2016-03-07 14:30 ` Javier Martinez Canillas
2016-03-11 13:09 ` Sylwester Nawrocki
2016-03-11 13:09 ` Sylwester Nawrocki
2016-03-11 14:39 ` Javier Martinez Canillas
2016-03-11 14:39 ` Javier Martinez Canillas
2016-03-11 14:39 ` Javier Martinez Canillas
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