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Groups > linux.kernel > #1624727
| From | Guenter Roeck <linux@roeck-us.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] ACPICA: Export mutex functions |
| Date | 2017-04-17 18:00 +0200 |
| Message-ID | <txheh-2tc-9@gated-at.bofh.it> (permalink) |
| References | <tvsdQ-64C-27@gated-at.bofh.it> <tvsxb-6br-3@gated-at.bofh.it> <tvxZT-1zC-7@gated-at.bofh.it> <txbix-7rC-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hi,
On Mon, Apr 17, 2017 at 09:39:35AM +0000, Zheng, Lv wrote:
> Hi,
>
> > From: Guenter Roeck [mailto:linux@roeck-us.net]
> > Subject: Re: [PATCH] ACPICA: Export mutex functions
> >
> > On Wed, Apr 12, 2017 at 03:29:55PM +0000, Moore, Robert wrote:
> > > The ACPICA mutex functions are based on the host OS functions, so they don't really buy you anything.
> > You should just use the native Linux functions.
> > >
> >
> > You mean they don't really acquire the requested ACPI mutex,
> > and the underlying DSDT which declares and uses the mutex
> > just ignores if the mutex was acquired by acpi_acquire_mutex() ?
> >
> > To clarify: You are saying that code such as
> >
> > acpi_status status;
> >
> > status = acpi_acquire_mutex(NULL, "\\_SB.PCI0.SBRG.SIO1.MUT0", 0x10);
> > if (ACPI_FAILURE(status)) {
> > pr_err("Failed to acquire ACPI mutex\n");
> > return -EBUSY;
> > }
>
> Why do you need to access \_SB.PCI0.SBRG.SIO1.MUT0?
> OSPM should only invoke entry methods predefined by ACPI spec or whatever specs.
> There shouldn't be any needs that a driver acquires an arbitrary AML mutex.
> You do not seem to have justified the usage model, IMO.
>
I am sorry, I have no idea how to do that. I can see that the resource in
question (IO address 0x2e/0x2f) is accessed from the DSDT, that the resource
is mutex protected, and that accesses to the same IO address from the Linux
kernel are unreliable unless I acquire the mutex in question. At the same time,
I can see that request_muxed_region() succeeds, so presumably ACPI does not
reserve the region for its exclusive use.
It may well be that the "official" response to this problem is "you must
not instantiate a watchdog, environmental monitor, or gpio driver (or anything
else provided by the Super-IO chip that requires access to those ports) on this
platform in Linux". Is that what you are suggesting ?
Thanks,
Guenter
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[PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-12 17:20 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-12 17:40 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-12 23:30 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-13 00:00 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-13 03:00 +0200
Re: [PATCH] ACPICA: Export mutex functions "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2017-04-15 00:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-15 01:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-17 11:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-17 11:50 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-17 16:10 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 01:40 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-17 18:00 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-17 19:20 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-17 21:30 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-17 21:50 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-17 22:50 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-17 23:10 +0200
Re: [PATCH] ACPICA: Export mutex functions "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-17 23:30 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-18 00:40 +0200
Re: [PATCH] ACPICA: Export mutex functions "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-18 01:00 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 02:00 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-18 06:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 09:10 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 09:20 +0200
Re: [PATCH] ACPICA: Export mutex functions Guenter Roeck <linux@roeck-us.net> - 2017-04-18 16:00 +0200
Re: [PATCH] ACPICA: Export mutex functions "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2017-04-18 16:30 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-18 18:10 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-19 03:30 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-19 03:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 02:00 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 01:50 +0200
RE: [PATCH] ACPICA: Export mutex functions "Moore, Robert" <robert.moore@intel.com> - 2017-04-17 21:40 +0200
RE: [PATCH] ACPICA: Export mutex functions "Zheng, Lv" <lv.zheng@intel.com> - 2017-04-18 01:40 +0200
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