From: Will Deacon <will.deacon@arm.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Stephen Boyd <sboyd@codeaurora.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
Stepan Moskovchenko <stepanm@codeaurora.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] arm: vfp: Bounce undefined instructions in vectored mode
Date: Fri, 19 Sep 2014 02:40:01 +0100 [thread overview]
Message-ID: <20140919014001.GB20773@arm.com> (raw)
In-Reply-To: <20140918225531.GG5182@n2100.arm.linux.org.uk>
On Thu, Sep 18, 2014 at 11:55:31PM +0100, Russell King - ARM Linux wrote:
> On Thu, Sep 18, 2014 at 02:43:12PM -0700, Stephen Boyd wrote:
> > From: Stepan Moskovchenko <stepanm@codeaurora.org>
> >
> > Certain ARM CPU implementations (e.g. Cortex-A15) may not raise a
> > floating- point exception whenever deprecated short-vector VFP
> > instructions are executed. Instead these instructions are treated
> > as UNALLOCATED. Change the VFP exception handling code to emulate
> > short-vector instructions even if FPEXC exception bits are not
> > set.
>
> Purely out of interest, how much use do these instructions have in
> real programs?
They're seldom used, but there are apps in the app store that use short
vectors to play music.
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/3] arm: vfp: Bounce undefined instructions in vectored mode
Date: Fri, 19 Sep 2014 02:40:01 +0100 [thread overview]
Message-ID: <20140919014001.GB20773@arm.com> (raw)
In-Reply-To: <20140918225531.GG5182@n2100.arm.linux.org.uk>
On Thu, Sep 18, 2014 at 11:55:31PM +0100, Russell King - ARM Linux wrote:
> On Thu, Sep 18, 2014 at 02:43:12PM -0700, Stephen Boyd wrote:
> > From: Stepan Moskovchenko <stepanm@codeaurora.org>
> >
> > Certain ARM CPU implementations (e.g. Cortex-A15) may not raise a
> > floating- point exception whenever deprecated short-vector VFP
> > instructions are executed. Instead these instructions are treated
> > as UNALLOCATED. Change the VFP exception handling code to emulate
> > short-vector instructions even if FPEXC exception bits are not
> > set.
>
> Purely out of interest, how much use do these instructions have in
> real programs?
They're seldom used, but there are apps in the app store that use short
vectors to play music.
Will
next prev parent reply other threads:[~2014-09-19 1:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-18 21:43 [PATCH 0/3] Krait VFP fixes Stephen Boyd
2014-09-18 21:43 ` Stephen Boyd
2014-09-18 21:43 ` [PATCH 1/3] ARM: vfp: Workaround bad MVFR1 register on some Kraits Stephen Boyd
2014-09-18 21:43 ` Stephen Boyd
2014-09-18 21:43 ` [PATCH 2/3] ARM: vfp: fix VFPv3 hwcap detection on non-ARM vfp implementations Stephen Boyd
2014-09-18 21:43 ` Stephen Boyd
2014-09-18 22:46 ` Russell King - ARM Linux
2014-09-18 22:46 ` Russell King - ARM Linux
2014-09-19 18:24 ` Stephen Boyd
2014-09-19 18:24 ` Stephen Boyd
2014-10-01 17:54 ` Stephen Boyd
2014-10-01 17:54 ` Stephen Boyd
2014-10-08 12:49 ` Will Deacon
2014-10-08 12:49 ` Will Deacon
2014-10-01 21:50 ` Russell King - ARM Linux
2014-10-01 21:50 ` Russell King - ARM Linux
2014-10-01 22:09 ` Stephen Boyd
2014-10-01 22:09 ` Stephen Boyd
2014-09-18 21:43 ` [PATCH 3/3] arm: vfp: Bounce undefined instructions in vectored mode Stephen Boyd
2014-09-18 21:43 ` Stephen Boyd
2014-09-18 22:55 ` Russell King - ARM Linux
2014-09-18 22:55 ` Russell King - ARM Linux
2014-09-19 1:40 ` Will Deacon [this message]
2014-09-19 1:40 ` Will Deacon
2014-09-18 22:32 ` [PATCH 0/3] Krait VFP fixes Russell King - ARM Linux
2014-09-18 22:32 ` Russell King - ARM Linux
2014-09-19 16:29 ` Stephen Boyd
2014-09-19 16:29 ` Stephen Boyd
2014-09-21 16:40 ` Rob Clark
2014-09-21 16:40 ` Rob Clark
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=20140919014001.GB20773@arm.com \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=sboyd@codeaurora.org \
--cc=stepanm@codeaurora.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.