RE: [PATCH v2] ACPI: Leave Bus Master Arbitration enabled for suspend/resume

Moore, Robert
2012-07-08T20:33:34Z

> Bob, I think we should incorporate this into ACPICA, shouldn't we?
>
> Rafael

We are looking at it. Probably one of the Linux/ACPICA divergences that end up causing us grief.

> -----Original Message-----
> From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-
> owner@vger.kernel.org] On Behalf Of Rafael J. Wysocki
> Sent: Sunday, July 08, 2012 1:08 PM
> To: Jonathan Nieder; Moore, Robert
> Cc: Octavio Alvarez; Adrian Knoth; Shaohua Li; Brown, Len; linux-
> acpi@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v2] ACPI: Leave Bus Master Arbitration enabled for
> suspend/resume
>
> On Sunday, July 08, 2012, Jonathan Nieder wrote:
> > This is an old suspend/resume lockup fix:
> >
> > commit 2780cc4660e1
> > Author: Len Brown <len.brown@intel.com>
> > Date: Thu Dec 23 13:43:30 2004 -0500
> >
> > [ACPI] Fix suspend/resume lockup issue
> > by leaving Bus Master Arbitration enabled.
> > The ACPI spec mandates it be disabled only for C3.
> >
> > http://bugzilla.kernel.org/show_bug.cgi?id=3599
> >
> > Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
> > Signed-off-by: Len Brown <len.brown@intel.com>
> >
> > The bug snuck back in in commit 2feec47d4c5f (ACPICA: ACPI 5: Support
> > for new FADT SleepStatus, SleepControl registers, 2012-02-14),
> > presumably by copy/pasting a copy of the code without that fix for
> the
> > legacy case.
> >
> > On affected machines, after that commit, the machine locks up hard on
> > resume from suspend. The same fix as seven years ago still works.
> >
> > Addresses <https://bugzilla.kernel.org/show_bug.cgi?id=43641>.
> >
> > Reported-bisected-and-tested-by: Octavio Alvarez
> > <alvarezp@alvarezp.com>
> > Reported-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
> > Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
> > Cc: <stable@vger.kernel.org> # 3.4
> > ---
> > Rafael J. Wysocki wrote:
> >
> > > Can you please repost it with _both_ the changelog and the patch?
> >
> > Here you go. Sorry about that.
>
> Thanks!
>
> Applied to the linux-next branch of the linux-pm.git tree.
>
> I think I'll push it for v3.6, since the bug is serious and is a
> regression.
>
> Bob, I think we should incorporate this into ACPICA, shouldn't we?
>
> Rafael
>
>
> > drivers/acpi/acpica/hwsleep.c | 22 ----------------------
> > 1 file changed, 22 deletions(-)
> >
> > diff --git a/drivers/acpi/acpica/hwsleep.c
> > b/drivers/acpi/acpica/hwsleep.c index 0ed85cac3231..615996a36bed
> > 100644
> > --- a/drivers/acpi/acpica/hwsleep.c
> > +++ b/drivers/acpi/acpica/hwsleep.c
> > @@ -95,18 +95,6 @@ acpi_status acpi_hw_legacy_sleep(u8 sleep_state,
> u8 flags)
> > return_ACPI_STATUS(status);
> > }
> >
> > - if (sleep_state != ACPI_STATE_S5) {
> > - /*
> > - * Disable BM arbitration. This feature is contained within
> an
> > - * optional register (PM2 Control), so ignore a BAD_ADDRESS
> > - * exception.
> > - */
> > - status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE,
> 1);
> > - if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
> > - return_ACPI_STATUS(status);
> > - }
> > - }
> > -
> > /*
> > * 1) Disable/Clear all GPEs
> > * 2) Enable all wakeup GPEs
> > @@ -364,16 +352,6 @@ acpi_status acpi_hw_legacy_wake(u8 sleep_state,
> u8 flags)
> > [ACPI_EVENT_POWER_BUTTON].
> > status_register_id, ACPI_CLEAR_STATUS);
> >
> > - /*
> > - * Enable BM arbitration. This feature is contained within an
> > - * optional register (PM2 Control), so ignore a BAD_ADDRESS
> > - * exception.
> > - */
> > - status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
> > - if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
> > - return_ACPI_STATUS(status);
> > - }
> > -
> > acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST,
> ACPI_SST_WORKING);
> > return_ACPI_STATUS(status);
> > }
> >
>
> --
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