LKML Archive on
help / color / mirror / Atom feed
From: Moritz Fischer <>
To: Vinod Koul <>
Cc: Lars-Peter Clausen <>,
	Linux Kernel Mailing List <>,,
Subject: Re: [PATCH v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED
Date: Fri, 27 Apr 2018 08:15:32 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <20180427070830.GC6014@localhost>

Hi Vinod,

On Fri, Apr 27, 2018 at 12:08 AM, Vinod Koul <> 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.




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

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-26 17:40 Moritz Fischer
2018-04-27  5:11 ` Vinod Koul
2018-04-27  6:53   ` Lars-Peter Clausen
2018-04-27  7:08     ` Vinod Koul
2018-04-27 15:15       ` Moritz Fischer [this message]
2018-04-27 15:18         ` Lars-Peter Clausen
2018-04-28  5:10           ` Vinod Koul
2018-04-28 19:31             ` Moritz Fischer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='' \ \ \ \ \ \ \
    --subject='Re: [PATCH v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).