From: Russell King <rmk@arm.linux.org.uk>
To: Thomas Koeller <thomas.koeller@baslerweb.com>
Cc: linux-serial@vger.kernel.org
Subject: Re: [PATCH] 8250 driver interrupt sharing
Date: Thu, 28 Oct 2004 12:18:45 +0100 [thread overview]
Message-ID: <20041028121845.D3327@flint.arm.linux.org.uk> (raw)
In-Reply-To: <200410281317.41817.thomas.koeller@baslerweb.com>; from thomas.koeller@baslerweb.com on Thu, Oct 28, 2004 at 01:17:41PM +0200
On Thu, Oct 28, 2004 at 01:17:41PM +0200, Thomas Koeller wrote:
> On Thursday 28 October 2004 13:00, Russell King wrote:
> > On Thu, Oct 28, 2004 at 01:01:58PM +0200, Thomas Koeller wrote:
> > > here is a little patch that causes the driver to no longer pretend having
> > > handled an interrupt if none of the ports actually interrupted. I am
> > > currently doing a port to a platform where I want (actually, have) to
> > > share a single interrupt between serial ports and other devices. The
> > > patch is against kernel version 2.6.9.
> >
> > You can only share serial port interrupts with other devices if the
> > interrupt controller input is level sensitive rather than edge
> > sensitive. If it is edge sensitive, then you'll run into problems.
>
> On my target platform, interrupts are indeed level sensitive, so this
> should not be a problem (for me).
Ok - that's fine.
> Does this problem somehow invalidate my patch?
Not really, but if you were using edge triggering, that would invalidate
your idea that you could share serial port interrupts reliably with other
devices.
> Even if interrupts were edge sensitive, returning IRQ_NONE should ok,
> or not?
It should be fine.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
2.6 Serial core
next prev parent reply other threads:[~2004-10-28 11:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-28 11:01 [PATCH] 8250 driver interrupt sharing Thomas Koeller
2004-10-28 11:00 ` Russell King
2004-10-28 11:17 ` Thomas Koeller
2004-10-28 11:18 ` Russell King [this message]
2004-11-01 12:10 ` Russell King
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