ACPI fixes for v4.1-rc4

- The recent ACPICA commit that set the ACPI _REV return value to 2
    (which is the value always used by Windows and now mandated by the
    spec too) in order to prevent the firmware people from using it to
    play tricks with us caused a serious audio regression to happen on
    Dell XPS 13 (the AML on that machine uses the _REV return value to
    decide how to expose audio to the OS and does that to hide the
    lack of proper support for its I2S audio in Linux), so revert that
    commit for now and we'll revisit the issue in the next cycle.
 
  - Ensure that the ordering of acpi_reserve_resources() with respect
    to the rest of the ACPI initialization sequence will always be
    the same, or the IO or memory region occupied by the ACPI fixed
    registers may be assigned to a PCI host bridge as a result of
    a race and random breakage ensues going forward.
 
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Merge tag 'pm+acpi-4.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI fixes from Rafael Wysocki:
 "Two fixes here, one revert of a recent ACPICA commit that broke audio
  support on one Dell machine and a fix for a long-standing issue that
  may cause systems to break randomly during boot.

  Specifics:

   - The recent ACPICA commit that set the ACPI _REV return value to 2
     (which is the value always used by Windows and now mandated by the
     spec too) in order to prevent the firmware people from using it to
     play tricks with us caused a serious audio regression to happen on
     Dell XPS 13 (the AML on that machine uses the _REV return value to
     decide how to expose audio to the OS and does that to hide the lack
     of proper support for its I2S audio in Linux), so revert that
     commit for now and we'll revisit the issue in the next cycle.

   - Ensure that the ordering of acpi_reserve_resources() with respect
     to the rest of the ACPI initialization sequence will always be the
     same, or the IO or memory region occupied by the ACPI fixed
     registers may be assigned to a PCI host bridge as a result of a
     race and random breakage ensues going forward"

* tag 'pm+acpi-4.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPICA: Permanently set _REV to the value '2'."
  ACPI / init: Fix the ordering of acpi_reserve_resources()
This commit is contained in:
Linus Torvalds 2015-05-14 18:40:16 -07:00
commit f0897f4cc0
2 changed files with 5 additions and 14 deletions

View File

@ -102,19 +102,12 @@ const struct acpi_predefined_names acpi_gbl_pre_defined_names[] = {
{"_SB_", ACPI_TYPE_DEVICE, NULL},
{"_SI_", ACPI_TYPE_LOCAL_SCOPE, NULL},
{"_TZ_", ACPI_TYPE_DEVICE, NULL},
/*
* March, 2015:
* The _REV object is in the process of being deprecated, because
* other ACPI implementations permanently return 2. Thus, it
* has little or no value. Return 2 for compatibility with
* other ACPI implementations.
*/
{"_REV", ACPI_TYPE_INTEGER, ACPI_CAST_PTR(char, 2)},
{"_REV", ACPI_TYPE_INTEGER, (char *)ACPI_CA_SUPPORT_LEVEL},
{"_OS_", ACPI_TYPE_STRING, ACPI_OS_NAME},
{"_GL_", ACPI_TYPE_MUTEX, ACPI_CAST_PTR(char, 1)},
{"_GL_", ACPI_TYPE_MUTEX, (char *)1},
#if !defined (ACPI_NO_METHOD_EXECUTION) || defined (ACPI_CONSTANT_EVAL_ONLY)
{"_OSI", ACPI_TYPE_METHOD, ACPI_CAST_PTR(char, 1)},
{"_OSI", ACPI_TYPE_METHOD, (char *)1},
#endif
/* Table terminator */

View File

@ -182,7 +182,7 @@ static void __init acpi_request_region (struct acpi_generic_address *gas,
request_mem_region(addr, length, desc);
}
static int __init acpi_reserve_resources(void)
static void __init acpi_reserve_resources(void)
{
acpi_request_region(&acpi_gbl_FADT.xpm1a_event_block, acpi_gbl_FADT.pm1_event_length,
"ACPI PM1a_EVT_BLK");
@ -211,10 +211,7 @@ static int __init acpi_reserve_resources(void)
if (!(acpi_gbl_FADT.gpe1_block_length & 0x1))
acpi_request_region(&acpi_gbl_FADT.xgpe1_block,
acpi_gbl_FADT.gpe1_block_length, "ACPI GPE1_BLK");
return 0;
}
device_initcall(acpi_reserve_resources);
void acpi_os_printf(const char *fmt, ...)
{
@ -1845,6 +1842,7 @@ acpi_status __init acpi_os_initialize(void)
acpi_status __init acpi_os_initialize1(void)
{
acpi_reserve_resources();
kacpid_wq = alloc_workqueue("kacpid", 0, 1);
kacpi_notify_wq = alloc_workqueue("kacpi_notify", 0, 1);
kacpi_hotplug_wq = alloc_ordered_workqueue("kacpi_hotplug", 0);