From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Archit Taneja <archit@ti.com>
Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>
Subject: Re: [PATCH 2/5] OMAPFB: simplify locking
Date: Thu, 13 Dec 2012 11:17:17 +0000 [thread overview]
Message-ID: <50C9B93D.3020601@ti.com> (raw)
In-Reply-To: <1354881309-17625-2-git-send-email-tomi.valkeinen@ti.com>
[-- Attachment #1: Type: text/plain, Size: 983 bytes --]
On 2012-12-07 13:55, Tomi Valkeinen wrote:
> Kernel lock verification code has lately detected possible circular
> locking in omapfb. The exact problem is unclear, but omapfb's current
> locking seems to be overly complex.
>
> This patch simplifies the locking in the following ways:
>
> - Remove explicit omapfb mem region locking. I couldn't figure out the
> need for this, as long as we take care to take omapfb lock.
>
> - Get omapfb lock always, even if the operation is possibly only related
> to one fb_info. Better safe than sorry, and normally there's only one
> user for the fb so this shouldn't matter.
>
> - Make sure fb_info lock is taken first, then omapfb lock.
>
> With this patch the warnings about possible circular locking does not
> happen anymore.
I'm dropping this patch, for some reason it causes huge latencies with
two processes using separate fbs. I guess there's need for the more
precise locking, after all.
Tomi
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 899 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Archit Taneja <archit@ti.com>
Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>
Subject: Re: [PATCH 2/5] OMAPFB: simplify locking
Date: Thu, 13 Dec 2012 13:17:17 +0200 [thread overview]
Message-ID: <50C9B93D.3020601@ti.com> (raw)
In-Reply-To: <1354881309-17625-2-git-send-email-tomi.valkeinen@ti.com>
[-- Attachment #1: Type: text/plain, Size: 983 bytes --]
On 2012-12-07 13:55, Tomi Valkeinen wrote:
> Kernel lock verification code has lately detected possible circular
> locking in omapfb. The exact problem is unclear, but omapfb's current
> locking seems to be overly complex.
>
> This patch simplifies the locking in the following ways:
>
> - Remove explicit omapfb mem region locking. I couldn't figure out the
> need for this, as long as we take care to take omapfb lock.
>
> - Get omapfb lock always, even if the operation is possibly only related
> to one fb_info. Better safe than sorry, and normally there's only one
> user for the fb so this shouldn't matter.
>
> - Make sure fb_info lock is taken first, then omapfb lock.
>
> With this patch the warnings about possible circular locking does not
> happen anymore.
I'm dropping this patch, for some reason it causes huge latencies with
two processes using separate fbs. I guess there's need for the more
precise locking, after all.
Tomi
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 899 bytes --]
next prev parent reply other threads:[~2012-12-13 11:17 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-07 11:55 [PATCH 1/5] OMAPFB: remove exported udpate window Tomi Valkeinen
2012-12-07 11:55 ` Tomi Valkeinen
2012-12-07 11:55 ` [PATCH 2/5] OMAPFB: simplify locking Tomi Valkeinen
2012-12-07 11:55 ` Tomi Valkeinen
2012-12-07 12:53 ` Ville Syrjälä
2012-12-07 12:53 ` Ville Syrjälä
2012-12-07 13:42 ` Tomi Valkeinen
2012-12-07 13:42 ` Tomi Valkeinen
2012-12-07 14:16 ` Tomi Valkeinen
2012-12-07 14:16 ` Tomi Valkeinen
2012-12-07 14:45 ` Ville Syrjälä
2012-12-07 14:45 ` Ville Syrjälä
2012-12-13 11:17 ` Tomi Valkeinen [this message]
2012-12-13 11:17 ` Tomi Valkeinen
2012-12-07 11:55 ` [PATCH 3/5] OMAPFB: remove warning when trying to alloc at certain paddress Tomi Valkeinen
2012-12-07 11:55 ` Tomi Valkeinen
2012-12-07 11:55 ` [PATCH 4/5] OMAPDSS: manage output-dssdev connection in output drivers Tomi Valkeinen
2012-12-07 11:55 ` Tomi Valkeinen
2012-12-07 11:55 ` [PATCH 5/5] OMAPFB: connect ovl managers to all dssdevs Tomi Valkeinen
2012-12-07 11:55 ` Tomi Valkeinen
2012-12-10 7:34 ` Archit Taneja
2012-12-10 7:46 ` Archit Taneja
2012-12-10 8:03 ` Tomi Valkeinen
2012-12-10 8:03 ` Tomi Valkeinen
2012-12-10 9:54 ` Archit Taneja
2012-12-10 9:55 ` Archit Taneja
2012-12-10 10:07 ` Tomi Valkeinen
2012-12-10 10:07 ` Tomi Valkeinen
2012-12-10 10:53 ` Archit Taneja
2012-12-10 10:54 ` Archit Taneja
2012-12-10 11:03 ` Tomi Valkeinen
2012-12-10 11:03 ` Tomi Valkeinen
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=50C9B93D.3020601@ti.com \
--to=tomi.valkeinen@ti.com \
--cc=archit@ti.com \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=ville.syrjala@linux.intel.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 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.