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From: Lars-Peter Clausen <lars@metafoo.de>
To: Moritz Fischer <moritz.fischer.private@gmail.com>,
	Vinod Koul <vinod.koul@intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	dmaengine@vger.kernel.org, dan.j.williams@intel.com
Subject: [v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED
Date: Fri, 27 Apr 2018 17:18:29 +0200	[thread overview]
Message-ID: <716956a2-a4f4-9cbd-8761-8db477f1dfc0@metafoo.de> (raw)

On 04/27/2018 05:15 PM, Moritz Fischer wrote:
> Hi Vinod,
> 
> On Fri, Apr 27, 2018 at 12:08 AM, Vinod Koul <vinod.koul@intel.com> wrote:
>> On Fri, Apr 27, 2018 at 08:53:39AM +0200, Lars-Peter Clausen wrote:
>>> On 04/27/2018 07:11 AM, Vinod Koul wrote:
>>>> On Thu, Apr 26, 2018 at 10:40:00AM -0700, Moritz Fischer wrote:
>>>>> Request IRQ with IRQF_SHARED flag. This works since the interrupt
>>>>> handler already checks if there is an actual IRQ pending and returns
>>>>> IRQ_NONE otherwise.
>>>>
>>>> hmmm what are we trying to fix here? Is your device on a shared line or not?
>>>
>>> IRQF_SHARED does not mean that the IRQ is on a shared line. It means that
>>> the driver can handle it if the IRQ is on a shared line. Since the driver
>>> can handle it setting the flag is a good idea since this enables usecases
>>> where the line is shared.
>>
>> Yes that is correct indeed, but what is the motivation for the change.
>>
>> If you never expect this to be in shared environment why to do this?
>> Sorry but "it works" is not a good enough reason for this change, to enable
>> usecases where the line is shared is a good reason :)
> 
> Remember, this is an FPGA soft core. I happen to have a design [1] where it
> is hooked up with multiple of them on one IRQ line, so to make this work,
> I need this change.

I think what Vinod is asking for is a change to the commit message saying
that "this change enables the driver to be used with devices where the
interrupt line is shared".
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WARNING: multiple messages have this Message-ID
From: Lars-Peter Clausen <lars@metafoo.de>
To: Moritz Fischer <moritz.fischer.private@gmail.com>,
	Vinod Koul <vinod.koul@intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	dmaengine@vger.kernel.org, dan.j.williams@intel.com
Subject: Re: [PATCH v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED
Date: Fri, 27 Apr 2018 17:18:29 +0200	[thread overview]
Message-ID: <716956a2-a4f4-9cbd-8761-8db477f1dfc0@metafoo.de> (raw)
In-Reply-To: <CAJYdmeO=k06MJi1L8++BC_zPqeb-BkrT=a7GOOCUE17Tk093NA@mail.gmail.com>

On 04/27/2018 05:15 PM, Moritz Fischer wrote:
> Hi Vinod,
> 
> On Fri, Apr 27, 2018 at 12:08 AM, Vinod Koul <vinod.koul@intel.com> wrote:
>> On Fri, Apr 27, 2018 at 08:53:39AM +0200, Lars-Peter Clausen wrote:
>>> On 04/27/2018 07:11 AM, Vinod Koul wrote:
>>>> On Thu, Apr 26, 2018 at 10:40:00AM -0700, Moritz Fischer wrote:
>>>>> Request IRQ with IRQF_SHARED flag. This works since the interrupt
>>>>> handler already checks if there is an actual IRQ pending and returns
>>>>> IRQ_NONE otherwise.
>>>>
>>>> hmmm what are we trying to fix here? Is your device on a shared line or not?
>>>
>>> IRQF_SHARED does not mean that the IRQ is on a shared line. It means that
>>> the driver can handle it if the IRQ is on a shared line. Since the driver
>>> can handle it setting the flag is a good idea since this enables usecases
>>> where the line is shared.
>>
>> Yes that is correct indeed, but what is the motivation for the change.
>>
>> If you never expect this to be in shared environment why to do this?
>> Sorry but "it works" is not a good enough reason for this change, to enable
>> usecases where the line is shared is a good reason :)
> 
> Remember, this is an FPGA soft core. I happen to have a design [1] where it
> is hooked up with multiple of them on one IRQ line, so to make this work,
> I need this change.

I think what Vinod is asking for is a change to the commit message saying
that "this change enables the driver to be used with devices where the
interrupt line is shared".

             reply	other threads:[~2018-04-27 15:18 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 15:18 Lars-Peter Clausen [this message]
2018-04-27 15:18 ` [PATCH v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED Lars-Peter Clausen
  -- strict thread matches above, loose matches on Subject: below --
2018-04-28 19:31 [v2] " mdf
2018-04-28 19:31 ` [PATCH v2] " Moritz Fischer
2018-04-28  5:10 [v2] " Vinod Koul
2018-04-28  5:10 ` [PATCH v2] " Vinod Koul
2018-04-27 15:15 [v2] " Moritz Fischer
2018-04-27 15:15 ` [PATCH v2] " Moritz Fischer
2018-04-27  7:08 [v2] " Vinod Koul
2018-04-27  7:08 ` [PATCH v2] " Vinod Koul
2018-04-27  6:53 [v2] " Lars-Peter Clausen
2018-04-27  6:53 ` [PATCH v2] " Lars-Peter Clausen
2018-04-27  5:11 [v2] " Vinod Koul
2018-04-27  5:11 ` [PATCH v2] " Vinod Koul
2018-04-26 17:40 [v2] " mdf
2018-04-26 17:40 ` [PATCH v2] " Moritz Fischer

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