From: okaya@codeaurora.org
To: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com,
eric.auger@linaro.org, mark.rutland@arm.com,
devicetree@vger.kernel.org,
Baptiste Reynal <b.reynal@virtualopensystems.com>,
vikrams@codeaurora.org, marc.zyngier@arm.com,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
vinod.koul@intel.com,
Alex Williamson <alex.williamson@redhat.com>,
agross@codeaurora.org, Dan Carpenter <dan.carpenter@oracle.com>,
shankerd@codeaurora.org
Subject: Re: [PATCH V3 1/3] vfio, platform: add support for ACPI while detecting the reset driver
Date: Tue, 29 Mar 2016 06:59:15 -0400 [thread overview]
Message-ID: <e736f6bc775cdca8a4bb0dab20654823@codeaurora.org> (raw)
In-Reply-To: <98854818.NJS35fvhsb@wuerfel>
On 2016-03-29 05:25, Arnd Bergmann wrote:
> On Monday 28 March 2016 09:35:22 Sinan Kaya wrote:
>> The code is using the compatible DT string to associate a reset driver
>> with
>> the actual device itself. The compatible string does not exist on ACPI
>> based systems. HID is the unique identifier for a device driver
>> instead.
>> The change allows a driver to register with DT compatible string or
>> ACPI
>> HID and then match the object with one of these conditions.
>>
>> Rules for loading the reset driver are as follow:
>> - ACPI HID needs match for ACPI systems
>> - DT compat needs to match for OF systems
>>
>> Tested-by: Eric Auger <eric.auger@linaro.org> (device tree only)
>> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> (ACPI only)
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>>
>
>
> This really feels wrong for two reasons:
>
> * device assignment of non-PCI devices is really special and doesn't
> seem to make sense on general purpose servers that would be the
> target
> for ACPI normally
Why is it special? Acpi is not equal to pci. Platform devices are first
class devices too. Especially, _cls was introduced for this reason.
>
> * If there is indeed a requirement for ACPI to handle something like
> this,
> it should be part of the ACPI spec, with a well-defined method of
> handling
> reset, rather than having to add a device specific hack for each
> device separately.
>
I see. Normally, this is done by calling _rst method. AFAIK, Linux
doesn’t support _rst. I can check its presence and call it if it is
there.
> Arnd
WARNING: multiple messages have this Message-ID (diff)
From: okaya@codeaurora.org (okaya at codeaurora.org)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V3 1/3] vfio, platform: add support for ACPI while detecting the reset driver
Date: Tue, 29 Mar 2016 06:59:15 -0400 [thread overview]
Message-ID: <e736f6bc775cdca8a4bb0dab20654823@codeaurora.org> (raw)
In-Reply-To: <98854818.NJS35fvhsb@wuerfel>
On 2016-03-29 05:25, Arnd Bergmann wrote:
> On Monday 28 March 2016 09:35:22 Sinan Kaya wrote:
>> The code is using the compatible DT string to associate a reset driver
>> with
>> the actual device itself. The compatible string does not exist on ACPI
>> based systems. HID is the unique identifier for a device driver
>> instead.
>> The change allows a driver to register with DT compatible string or
>> ACPI
>> HID and then match the object with one of these conditions.
>>
>> Rules for loading the reset driver are as follow:
>> - ACPI HID needs match for ACPI systems
>> - DT compat needs to match for OF systems
>>
>> Tested-by: Eric Auger <eric.auger@linaro.org> (device tree only)
>> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> (ACPI only)
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>>
>
>
> This really feels wrong for two reasons:
>
> * device assignment of non-PCI devices is really special and doesn't
> seem to make sense on general purpose servers that would be the
> target
> for ACPI normally
Why is it special? Acpi is not equal to pci. Platform devices are first
class devices too. Especially, _cls was introduced for this reason.
>
> * If there is indeed a requirement for ACPI to handle something like
> this,
> it should be part of the ACPI spec, with a well-defined method of
> handling
> reset, rather than having to add a device specific hack for each
> device separately.
>
I see. Normally, this is done by calling _rst method. AFAIK, Linux
doesn?t support _rst. I can check its presence and call it if it is
there.
> Arnd
next prev parent reply other threads:[~2016-03-29 10:59 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-28 13:35 [PATCH V3 0/3] vfio, platform: add HIDMA and ACPI support Sinan Kaya
2016-03-28 13:35 ` Sinan Kaya
2016-03-28 13:35 ` [PATCH V3 1/3] vfio, platform: add support for ACPI while detecting the reset driver Sinan Kaya
2016-03-28 13:35 ` Sinan Kaya
2016-03-29 9:25 ` Arnd Bergmann
2016-03-29 9:25 ` Arnd Bergmann
2016-03-29 10:59 ` okaya [this message]
2016-03-29 10:59 ` okaya at codeaurora.org
2016-03-29 11:25 ` Arnd Bergmann
2016-03-29 11:25 ` Arnd Bergmann
2016-03-29 12:15 ` okaya-sgV2jX0FEOL9JmXXK+q4OQ
2016-03-29 12:15 ` okaya
2016-03-29 12:15 ` okaya at codeaurora.org
2016-03-29 12:44 ` Arnd Bergmann
2016-03-29 12:44 ` Arnd Bergmann
2016-05-01 17:55 ` Sinan Kaya
2016-05-01 17:55 ` Sinan Kaya
2016-03-28 13:35 ` [PATCH V3 2/3] vfio, platform: make reset driver a requirement by default Sinan Kaya
2016-03-28 13:35 ` Sinan Kaya
2016-03-28 13:35 ` [PATCH V3 3/3] vfio, platform: add QTI HIDMA reset driver Sinan Kaya
2016-03-28 13:35 ` Sinan Kaya
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