linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: David Brownell <david-b@pacbell.net>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org, linux-usb-devel@lists.sourceforge.net
Subject: Re: [PATCH 1/2] usb: Remove broken optimisation in OHCI IRQ handler
Date: Thu, 6 Dec 2007 08:55:27 -0800	[thread overview]
Message-ID: <200712060855.27977.david-b@pacbell.net> (raw)
In-Reply-To: <20071125225542.880F2DDF13@ozlabs.org>

On Sunday 25 November 2007, Benjamin Herrenschmidt wrote:
> While there, any reason why we do the read of the interenable register
> and mask ? Is that actually useful in practice ? I haven't removed it
> but it might be a good candidate if we want to save on MMIO reads.

The code uses that register to keep track of which IRQs are enabled
or disabled, and those enabled IRQs are changed from time to time.

I don't know of any good reason not to keep an in-memory copy of the
resulting mask, though I'd keep an eye out for chip errata.

- Dave

  reply	other threads:[~2007-12-06 17:22 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-25 22:54 [PATCH 1/2] usb: Remove broken optimisation in OHCI IRQ handler Benjamin Herrenschmidt
2007-12-06 16:55 ` David Brownell [this message]
2007-12-06 21:28 ` David Brownell

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=200712060855.27977.david-b@pacbell.net \
    --to=david-b@pacbell.net \
    --cc=benh@kernel.crashing.org \
    --cc=linux-usb-devel@lists.sourceforge.net \
    --cc=linuxppc-dev@ozlabs.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;
as well as URLs for NNTP newsgroup(s).