Messages in this thread | | | From | Ferry Toth <> | Subject | Re: [PATCH] ACPICA: make acpi_load_table() return table index | Date | Fri, 13 Sep 2019 18:48:28 +0200 |
| |
Hello all,
Sorry to have sent our message with cancelled e-mail address. I have correct this now.
Op 13-09-19 om 17:12 schreef Shevchenko, Andriy: > On Fri, Sep 13, 2019 at 05:20:21PM +0300, Moore, Robert wrote: >> -----Original Message----- >> From: Nikolaus Voss [mailto:nv@vosn.de] >> Sent: Friday, September 13, 2019 12:44 AM >> To: Moore, Robert <robert.moore@intel.com> >> Cc: Shevchenko, Andriy <andriy.shevchenko@intel.com>; Schmauss, Erik <erik.schmauss@intel.com>; Rafael J. Wysocki <rjw@rjwysocki.net>; Len Brown <lenb@kernel.org>; Jacek Anaszewski <jacek.anaszewski@gmail.com>; Pavel Machek <pavel@ucw.cz>; Dan Murphy <dmurphy@ti.com>; linux-acpi@vger.kernel.org; devel@acpica.org; linux-kernel@vger.kernel.org; Ferry Toth <ftoth@telfort.nl>; nikolaus.voss@loewensteinmedical.de >> Subject: RE: [PATCH] ACPICA: make acpi_load_table() return table index >> >> Bob, >> >> On Thu, 12 Sep 2019, Moore, Robert wrote: >>> The ability to unload an ACPI table (especially AML tables such as >>> SSDTs) is in the process of being deprecated in ACPICA -- since it is >>> also deprecated in the current ACPI specification. This is being done >>> because of the difficulty of deleting the namespace entries for the >>> table. FYI, Windows does not properly support this function either. >> >> ok, I see it can be a problem to unload an AML table with all it's consequences e.g. with respect to driver unregistering in setups with complex dependencies. It will only work properly under certain conditions >> - nevertheless acpi_tb_unload_table() is still exported in ACPICA and we should get this working as it worked before. >> >> AcpiTbUnloadTable is not exported, it is an internal interface only -- as >> recognized by the "AcpiTb". > > In Linux it became a part of ABI when the > > commit 772bf1e2878ecfca0d1f332071c83e021dd9cf01 > Author: Jan Kiszka <jan.kiszka@siemens.com> > Date: Fri Jun 9 20:36:31 2017 +0200 > > ACPI: configfs: Unload SSDT on configfs entry removal > > appeared in the kernel.
And the commit message explains quite well why it is an important feature:
"This allows to change SSDTs without rebooting the system. It also allows to destroy devices again that a dynamically loaded SSDT created.
This is widely similar to the DT overlay behavior."
>> I'm not sure that I want to change the interface >> to AcpiLoadTable just for something that is being deprecated. Already, we >> throw an ACPI_EXCEPTION if the Unload operator is encountered in the AML byte >> stream. The same thing with AcpiUnloadParentTable - it is being deprecated. >> >> ACPI_EXCEPTION ((AE_INFO, AE_NOT_IMPLEMENTED, >> "AML Unload operator is not supported")); >
| |