linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: sboyd@codeaurora.org (Stephen Boyd)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 3/3] ARM: Work around faulty ISAR0 register in some Krait CPUs
Date: Mon, 18 Mar 2013 11:46:27 -0700	[thread overview]
Message-ID: <51476103.40901@codeaurora.org> (raw)
In-Reply-To: <20130318183435.GD31193@mudshark.cambridge.arm.com>

On 03/18/13 11:34, Will Deacon wrote:
> On Mon, Mar 18, 2013 at 06:28:57PM +0000, Stephen Boyd wrote:
>> From: Stepan Moskovchenko <stepanm@codeaurora.org>
>>
>> Some early versions of the Krait CPU design incorrectly indicate
>> that they only support the UDIV and SDIV instructions in Thumb
>> mode when they actually support them in ARM and Thumb mode. It
>> seems that these CPUs follow the DDI0406B ARM ARM which has two
>> possible values for the divide instructions field, instead of the
>> DDI0406C document which has three possible values.
>>
>> Work around this problem by checking the MIDR against Krait CPUs
>> with this faulty ISAR0 register and force the hwcaps to indicate
>> support in both modes.
>>
>> Cc: Will Deacon <will.deacon@arm.com>
>> Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
>> [sboyd: Rewrote commit text to reflect real reasoning now that
>> 	we autodetect udiv/sdiv]
>> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
>> ---
>>  arch/arm/mm/proc-v7.S | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
> Acked-by: Will Deacon <will.deacon@arm.com>
>

Thanks. Put all three in the patch tracker.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

      reply	other threads:[~2013-03-18 18:46 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-18 18:28 [PATCHv2 0/3] Detect UDIV/SDIV support from ISAR0 Stephen Boyd
2013-03-18 18:28 ` [PATCHv2 1/3] ARM: Clear IDIVT hwcap if CONFIG_ARM_THUMB=n Stephen Boyd
2013-03-18 18:28 ` [PATCHv2 2/3] ARM: Detect support for SDIV/UDIV from ISAR0 register Stephen Boyd
2013-04-18  9:10   ` Uwe Kleine-König
2013-05-06  9:30     ` [RFC PATCH] implement read_cpuid_ext for v7-M (Was: Re: [PATCHv2 2/3] ARM: Detect support for SDIV/UDIV from ISAR0) register Uwe Kleine-König
2013-05-06 17:31       ` Stephen Boyd
2013-05-07  9:22       ` Will Deacon
2013-05-07  9:35         ` Uwe Kleine-König
2013-05-07  9:52           ` Will Deacon
2013-05-07 10:56         ` Jonathan Austin
2013-05-07 12:40           ` Uwe Kleine-König
2013-05-07 12:54             ` Will Deacon
2013-05-07 10:30       ` Jonathan Austin
2013-03-18 18:28 ` [PATCHv2 3/3] ARM: Work around faulty ISAR0 register in some Krait CPUs Stephen Boyd
2013-03-18 18:34   ` Will Deacon
2013-03-18 18:46     ` Stephen Boyd [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=51476103.40901@codeaurora.org \
    --to=sboyd@codeaurora.org \
    --cc=linux-arm-kernel@lists.infradead.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).