public inbox for stable@vger.kernel.org
 help / color / mirror / Atom feed
From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Borislav Petkov <bp@alien8.de>
Cc: linux-kernel@vger.kernel.org, rafael@kernel.org, lenb@kernel.org,
	linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org,
	dave.hansen@linux.intel.com, tglx@linutronix.de, andi@lisas.de,
	puwen@hygon.cn, mario.limonciello@amd.com, peterz@infradead.org,
	rui.zhang@intel.com, gpiccoli@igalia.com,
	daniel.lezcano@linaro.org, ananth.narayan@amd.com,
	gautham.shenoy@amd.com, Calvin Ong <calvin.ong@amd.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH v2] x86,acpi: Limit "Dummy wait" workaround to older AMD and Intel processors
Date: Fri, 23 Sep 2022 21:55:02 +0530	[thread overview]
Message-ID: <f020defb-df73-35ff-5d97-c07773bafb67@amd.com> (raw)
In-Reply-To: <Yy3U0fQ0GZYZnMa1@zn.tnic>

Hello Boris,

On 9/23/2022 9:16 PM, Borislav Petkov wrote:
> On Fri, Sep 23, 2022 at 09:08:01PM +0530, K Prateek Nayak wrote:
>> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
>> index ef4775c6db01..fcd3617ed315 100644
>> --- a/arch/x86/include/asm/cpufeatures.h
>> +++ b/arch/x86/include/asm/cpufeatures.h
>> @@ -460,5 +460,6 @@
>>  #define X86_BUG_MMIO_UNKNOWN		X86_BUG(26) /* CPU is too old and its MMIO Stale Data status is unknown */
>>  #define X86_BUG_RETBLEED		X86_BUG(27) /* CPU is affected by RETBleed */
>>  #define X86_BUG_EIBRS_PBRSB		X86_BUG(28) /* EIBRS is vulnerable to Post Barrier RSB Predictions */
>> +#define X86_BUG_STPCLK			X86_BUG(29) /* STPCLK# signal does not get asserted in time during IOPORT based C-state entry */
> 
> What for?
> 
> Did you not see this thread?
> 
> https://lore.kernel.org/r/78d13a19-2806-c8af-573e-7f2625edfab8@intel.com
> 

Yes, I did see the patch, but Andreas replied to Dave's patch attached
in v1 saying that he had seen this issue with AMD Athlon on a VIA
chipset back in 2006. (https://lore.kernel.org/lkml/Yyy6l94G0O2B7Yh1@rhlx01.hs-esslingen.de/)
Therefore, Dave's patch is not sufficient.

Dave suggested the use of AMD vendor and family check, but Peter then
pointed out that we would also need the Hygon vendor check.

Hence I worked on the v2 which addressed these with the help of
X86_BUG_STPCLK so that we can avoid vendor specific checks inside the
common acpi code.
--
Thanks and Regards,
Prateek

  reply	other threads:[~2022-09-23 16:25 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-23 15:38 [PATCH v2] x86,acpi: Limit "Dummy wait" workaround to older AMD and Intel processors K Prateek Nayak
2022-09-23 15:46 ` Borislav Petkov
2022-09-23 16:25   ` K Prateek Nayak [this message]
2022-09-23 16:30     ` Borislav Petkov
2022-09-23 16:52       ` K Prateek Nayak
2022-09-26  8:19 ` David Laight
2022-09-26 12:07 ` Peter Zijlstra
2022-09-26 16:32   ` K Prateek Nayak
2022-09-26 19:55     ` Andreas Mohr

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=f020defb-df73-35ff-5d97-c07773bafb67@amd.com \
    --to=kprateek.nayak@amd.com \
    --cc=ananth.narayan@amd.com \
    --cc=andi@lisas.de \
    --cc=bp@alien8.de \
    --cc=calvin.ong@amd.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=dave.hansen@linux.intel.com \
    --cc=gautham.shenoy@amd.com \
    --cc=gpiccoli@igalia.com \
    --cc=lenb@kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mario.limonciello@amd.com \
    --cc=peterz@infradead.org \
    --cc=puwen@hygon.cn \
    --cc=rafael.j.wysocki@intel.com \
    --cc=rafael@kernel.org \
    --cc=rui.zhang@intel.com \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    /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