public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Magnus Damm <magnus.damm@gmail.com>, linux-kernel@vger.kernel.org
Cc: linux-sh@vger.kernel.org, benh@kernel.crashing.org,
	grant.likely@secretlab.ca, horms@verge.net.au,
	tglx@linutronix.de
Subject: Re: [PATCH] irqchip: Renesas IRQC driver
Date: Thu, 12 Dec 2013 02:36:28 +0300	[thread overview]
Message-ID: <52A8F6FC.40201@cogentembedded.com> (raw)
In-Reply-To: <20130227081501.30706.60471.sendpatchset@w520>

Hello.

On 02/27/2013 11:15 AM, Magnus Damm wrote:

> From: Magnus Damm <damm@opensource.se>

    Magnus, explain me one thing about your driver please.

> This patch adds a driver for external IRQ pins connected
> to the IRQC hardware block on recent SoCs from Renesas.
>
> The IRQC hardware block is used together with more
> recent ARM based SoCs using the GIC. As usual the GIC
> requires external IRQ trigger setup somewhere else
> which in this particular case happens to be IRQC.
>
> This driver implements the glue code needed to configure
> IRQ trigger and also handle mask/unmask and demux of
> external IRQ pins hooked up from the IRQC to the GIC.

    Judging on the R8A779x manual pictures, IRQn enter the SoC via IRQC, right?
Why then you call request_irq() on GIC interrupt numbers and expect an 
interrupt to "enter" from the GIC side, and then only read IRQC's 
DETECT_STATUS register to make sure the matching IRQn is really active (you 
call it demux, but I don't really see much of a demultiplexing there). This 
seems to me fundamentally broken, and is probably why the interrupt from PHY 
doesn't happen despite I set the interrupt type to active low via a call to 
irq_set_irq_type()...

> Tested on r8a73a4 but is designed to work with a wide
> range of SoCs. The driver requires one GIC SPI per
> external IRQ pin to operate.  Each driver instance
> will handle up to 32 external IRQ pins.

    Ah, so you've even tested it... I got an impression from your words that 
the driver hasn't been tested.

> The SoCs using this driver are currently mainly used
> together with regular platform devices so this driver
> allows configuration via platform data to support things
> like static interrupt base address. DT support will
> be added incrementally in the not so distant future.

> Signed-off-by: Magnus Damm <damm@opensource.se>

WBR, Sergei


      parent reply	other threads:[~2013-12-11 22:36 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-27  8:15 [PATCH] irqchip: Renesas IRQC driver Magnus Damm
2013-02-27  8:40 ` Simon Horman
2013-03-01  9:41 ` Simon Horman
2013-03-01 15:02 ` Guennadi Liakhovetski
2013-12-11 23:36 ` Sergei Shtylyov [this message]

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=52A8F6FC.40201@cogentembedded.com \
    --to=sergei.shtylyov@cogentembedded.com \
    --cc=benh@kernel.crashing.org \
    --cc=grant.likely@secretlab.ca \
    --cc=horms@verge.net.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=magnus.damm@gmail.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox