From: Oliver Neukum <Oliver.Neukum@lrz.uni-muenchen.de>
To: "Dmitry A. Fedorov" <D.A.Fedorov@inp.nsk.su>
Cc: Balbir Singh <balbir_soni@yahoo.com>, linux-kernel@vger.kernel.org
Subject: Re: Is it useful to support user level drivers
Date: Thu, 21 Jun 2001 17:19:06 +0200 [thread overview]
Message-ID: <01062117190601.02209@idun> (raw)
In-Reply-To: <Pine.SGI.4.10.10106212130280.3193032-100000@Sky.inp.nsk.su>
In-Reply-To: <Pine.SGI.4.10.10106212130280.3193032-100000@Sky.inp.nsk.su>
On Thursday, 21. June 2001 16:46, Dmitry A. Fedorov wrote:
> On Thu, 21 Jun 2001, Oliver Neukum wrote:
> > > Lastly an IRQ kernel module can disable_irq() from interrupt handler
> > > and enable it again only on explicit acknowledge from user.
> >
> > Unless you need that interrupt to be enabled to deliver the signal or let
>
> Need not. Signal and other event delivery mechanisms has nothing
> common with disable/enable_irq().
And how do you ensure that no interrupt is lost ?
In fact you now are likely to have a race condition reading device status or
the like.
> > userspace reenable the interrupt.
>
> "user acknowledge" is mean that.
>
> > In addition, how do you handle shared interrupts ?
>
> It is impossible, see my another message.
Which IMHO makes the concept pretty much useless.
Interrupt sharing is pretty much the norm today. And there is no evidence for
this to change in the near future. Rather the opposite seems to happen in
fact.
Which devices were you thinking of, that need a hardware IRQ and no kernel
driver ?
Regards
Oliver
next prev parent reply other threads:[~2001-06-21 15:21 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-21 10:41 Is it useful to support user level drivers Balbir Singh
2001-06-21 10:55 ` Tim Waugh
2001-06-21 11:04 ` Alan Cox
2001-06-21 12:43 ` Balbir Singh
2001-06-21 13:27 ` Alan Cox
2001-06-28 22:52 ` Pavel Machek
2001-06-21 12:45 ` Dmitry A. Fedorov
2001-06-21 13:24 ` Oliver Neukum
2001-06-21 14:46 ` Dmitry A. Fedorov
2001-06-21 15:19 ` Oliver Neukum [this message]
2001-06-22 4:19 ` Dmitry A. Fedorov
2001-06-22 7:28 ` Balbir Singh
2001-06-21 16:34 ` Abramo Bagnara
2001-06-21 17:27 ` Alan Cox
2001-06-21 19:59 ` Abramo Bagnara
2001-06-21 20:40 ` Richard B. Johnson
2001-06-21 20:54 ` Abramo Bagnara
2001-06-21 21:09 ` Oliver Neukum
2001-06-28 22:57 ` Pavel Machek
2001-06-21 13:28 ` Alan Cox
2001-06-21 14:03 ` Matthias Urlichs
2001-06-28 22:54 ` Pavel Machek
2001-06-21 14:20 ` Dmitry A. Fedorov
2001-06-21 11:38 ` Dmitry A. Fedorov
2001-06-21 13:50 ` john slee
2001-06-21 13:58 ` Matthias Urlichs
2001-06-21 14:21 ` john slee
2001-06-28 22:51 ` Pavel Machek
[not found] <mailman.993156181.18994.linux-kernel2news@redhat.com>
2001-06-21 22:06 ` Pete Zaitcev
2001-06-21 22:20 ` David S. Miller
2001-06-21 23:09 ` Mike Mackovitch
2001-06-21 23:22 ` David S. Miller
2001-06-21 23:50 ` Mike Mackovitch
2001-06-22 0:36 ` David S. Miller
2001-06-21 23:40 ` Richard B. Johnson
2001-06-22 0:30 ` Anders Larsen
2001-06-22 0:43 ` Richard B. Johnson
2001-06-25 0:06 ` Anders Larsen
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=01062117190601.02209@idun \
--to=oliver.neukum@lrz.uni-muenchen.de \
--cc=D.A.Fedorov@inp.nsk.su \
--cc=balbir_soni@yahoo.com \
--cc=linux-kernel@vger.kernel.org \
/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