All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andy Lutomirski <luto@amacapital.net>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: DRI Development <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH 17/25] drm: rip out drm_core_has_MTRR checks
Date: Fri, 9 Aug 2013 11:39:14 -0700	[thread overview]
Message-ID: <CALCETrVPVxvTBDHaFN6tRB-e2wi6duDRrkdBGOtqE270Wo_1Dg@mail.gmail.com> (raw)
In-Reply-To: <CAKMK7uG5WX+rm5x+Ro6r9x2AXFi=6jmbnCqEjpxcWpsWe0s2vQ@mail.gmail.com>

On Fri, Aug 9, 2013 at 11:36 AM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> On Fri, Aug 9, 2013 at 8:12 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>> On Thu, Aug 8, 2013 at 6:41 AM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>>> The new arch_phys_wc_add/del functions do the right thing both with
>>> and without MTRR support in the kernel. So we can drop these
>>> additional checks.
>>
>> If any of the new arch_phys_wc_add calls are reachable and if the
>> driver calls arch_phys_wc_add itself, then the lack of refcounting on
>> non-PAT systems may cause a problem.  (I don't understand the drm
>> stuff well enough to know whether that can actually happen.)
>
> This is only about compile-time options really. Somehow drm had the
> idea to use these check functions instead of #ifdef plus dummy static
> inline noop functions. David Herrmann just did the same patch for the
> agp stuff. So refcounting is of no concern here.

I feel like I'm missing something obvious here.  On nouveau, prior to
this patch, the drm maps code would not touch mtrrs.  Now it will.
Nouveau already calls arch_phys_wc_add, so if that maps code is
reached on the same resource, then there could be refcounting issues.

--Andy

> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch



-- 
Andy Lutomirski
AMA Capital Management, LLC

  reply	other threads:[~2013-08-09 18:39 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-08 13:41 [PATCH 00/25] drm cruft removal Daniel Vetter
2013-08-08 13:41 ` [PATCH 01/25] drm/omap: kill firstopen callback Daniel Vetter
2013-08-08 14:04   ` Rob Clark
2013-08-08 13:41 ` [PATCH 02/25] drm/radeon: kill firstopen callback for kms driver Daniel Vetter
2013-08-08 13:41 ` [PATCH 03/25] drm/imx: kill firstopen callback Daniel Vetter
2013-08-12 22:23   ` Greg Kroah-Hartman
2013-08-08 13:41 ` [PATCH 04/25] drm/vmwgfx: remove ->firstopen callback Daniel Vetter
2013-08-08 13:41 ` [PATCH 05/25] drm: don't call ->firstopen for KMS drivers Daniel Vetter
2013-08-08 13:41 ` [PATCH 06/25] drm: kill dev->driver->set_version Daniel Vetter
2013-08-08 14:10   ` Rob Clark
2013-08-08 13:41 ` [PATCH 07/25] drm: hide legacy sg cleanup better from common code Daniel Vetter
2013-08-08 13:41 ` [PATCH 08/25] drm: disallow legacy sg ioctls for modesetting drivers Daniel Vetter
2013-08-08 13:41 ` [PATCH 09/25] drm: mark dma setup/teardown as legacy systems Daniel Vetter
2013-08-08 13:41 ` [PATCH 10/25] drm: disallow legacy dma ioctls for modesetting drivers Daniel Vetter
2013-08-08 13:41 ` [PATCH 11/25] drm: mark context support as a legacy subsystem Daniel Vetter
2013-08-08 13:41 ` [PATCH 12/25] drm/vmwgfx: remove redundant clearing of driver->dma_quiescent Daniel Vetter
2013-08-08 13:41 ` [PATCH 13/25] drm: remove FASYNC support Daniel Vetter
2013-08-13 19:26   ` David Herrmann
2013-08-08 13:41 ` [PATCH 14/25] drm: rip out DRIVER_FB_DMA and related code Daniel Vetter
2013-08-08 13:41 ` [PATCH 15/25] drm: rip out a few unused DRIVER flags Daniel Vetter
2013-08-08 13:41 ` [PATCH 16/25] drm: remove a bunch of unused #defines from drmP.h Daniel Vetter
2013-08-08 13:41 ` [PATCH 17/25] drm: rip out drm_core_has_MTRR checks Daniel Vetter
2013-08-09 18:12   ` Andy Lutomirski
2013-08-09 18:36     ` Daniel Vetter
2013-08-09 18:39       ` Andy Lutomirski [this message]
2013-08-09 18:47         ` Daniel Vetter
2013-08-09 18:48           ` Andy Lutomirski
2013-08-15 12:44   ` David Herrmann
2013-08-08 13:41 ` [PATCH 18/25] drm/docs: rip out removed driver flags documentation Daniel Vetter
2013-08-08 13:41 ` [PATCH 19/25] drm: remove the dma_ioctl special-case Daniel Vetter
2013-08-13 18:05   ` David Herrmann
2013-08-08 13:41 ` [PATCH 20/25] drm/memory: don't export agp helpers Daniel Vetter
2013-08-08 13:41 ` [PATCH 21/25] drm: hollow-out GET_CLIENT ioctl Daniel Vetter
2013-08-08 13:41 ` [PATCH 22/25] drm: no-op out GET_STATS ioctl Daniel Vetter
2013-08-08 15:55   ` Eric Anholt
2013-08-09  9:05     ` Daniel Vetter
2013-08-08 13:41 ` [PATCH 23/25] drm: fix locking in gem debugfs/procfs file Daniel Vetter
2013-08-08 13:41 ` [PATCH 24/25] drm: remove procfs code, take 2 Daniel Vetter
2013-08-08 13:41 ` [PATCH 25/25] drm: move dev data clearing from drm_setup to lastclose Daniel Vetter
2013-08-13 18:12   ` David Herrmann

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=CALCETrVPVxvTBDHaFN6tRB-e2wi6duDRrkdBGOtqE270Wo_1Dg@mail.gmail.com \
    --to=luto@amacapital.net \
    --cc=daniel.vetter@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.