public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Alan Cox <alan@linux.intel.com>
To: Thierry Reding <treding@nvidia.com>
Cc: Nicholas Krause <xerofoify@gmail.com>,
	airlied@linux.ie, airlied@redhat.com, damien.lespiau@intel.com,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gpu:drm:Change calls to mdelay to msleep in the functions,send_pkg_prepare and send_pkg_done for the file,mdfld_dsi_pkg_sender.c
Date: Mon, 12 Jan 2015 16:14:49 +0000	[thread overview]
Message-ID: <1421079289.31978.34.camel@linux.intel.com> (raw)
In-Reply-To: <20150112161233.GC16118@ulmo.nvidia.com>

On Mon, 2015-01-12 at 17:12 +0100, Thierry Reding wrote:
> On Mon, Jan 12, 2015 at 01:29:27PM +0000, Alan Cox wrote:
> > On Sat, 2015-01-10 at 23:31 -0500, Nicholas Krause wrote:
> > > Changes various calls in the functions,send_pkg_prepare and send_pkg_done
> > > for mdelay to msleep. These changes are needed due to use working with
> > > various sleep modes supported by this hardware and thus needing to sleep
> > > for a small duration instead of using the respectful delay function due
> > > to the need to sleep rather then busy loop the CPU(s) and waste CPU cycles
> > > on the system that could be used to handle other tasks.
> > > 
> > > Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
> > 
> > NAK
> > 
> > Like every other TODO you've been mucking with at random this one is
> > there for a reason.
> > 
> > We can't sleep at this point.
> 
> From a quick look it seems like the only reason why we can't sleep is
> because sender->lock is a spinlock. But it would seem that it could
> simply be a mutex, in which case the delays could become sleeps.
> 
> Do you happen to remember if there were specific reasons to make this a
> spinlock rather than a mutex?

I don't remember the full details and since I don't currently have a
test platform for it, and its obsolete I don't want to touch it.

If someone else does fine, but they need to verify it on real hardware.

Alan



      reply	other threads:[~2015-01-12 16:15 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1420950664-18875-1-git-send-email-xerofoify@gmail.com>
2015-01-12 13:29 ` [PATCH] gpu:drm:Change calls to mdelay to msleep in the functions,send_pkg_prepare and send_pkg_done for the file,mdfld_dsi_pkg_sender.c Alan Cox
2015-01-12 16:12   ` Thierry Reding
2015-01-12 16:14     ` Alan Cox [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=1421079289.31978.34.camel@linux.intel.com \
    --to=alan@linux.intel.com \
    --cc=airlied@linux.ie \
    --cc=airlied@redhat.com \
    --cc=damien.lespiau@intel.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=treding@nvidia.com \
    --cc=xerofoify@gmail.com \
    /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