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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-12-01 23:50:16 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-12-01 23:50:16 +0100 |
commit | c50f13c672df758b59e026c15b9118f3ed46edc4 (patch) | |
tree | 994eb40c3da799b01988effd5f68039bfafacdfb /drivers/acpi/acpica/hwgpe.c | |
parent | ACPICA: Update version to 20141107. (diff) | |
download | linux-dev-c50f13c672df758b59e026c15b9118f3ed46edc4.tar.xz linux-dev-c50f13c672df758b59e026c15b9118f3ed46edc4.zip |
ACPICA: Save current masks of enabled GPEs after enable register writes
There is a race condition between acpi_hw_disable_all_gpes() or
acpi_enable_all_wakeup_gpes() and acpi_ev_asynch_enable_gpe() such
that if the latter wins the race, it may mistakenly enable a GPE
disabled by the former. This may lead to premature system wakeups
during system suspend and potentially to more serious consequences.
The source of the problem is how acpi_hw_low_set_gpe() works when
passed ACPI_GPE_CONDITIONAL_ENABLE as the second argument. In that
case, the GPE will be enabled if the corresponding bit is set in the
enable_for_run mask of the GPE enable register containing that bit.
However, acpi_hw_disable_all_gpes() and acpi_enable_all_wakeup_gpes()
don't modify the enable_for_run masks of GPE registers when writing
to them. In consequence, if acpi_ev_asynch_enable_gpe(), which
eventually calls acpi_hw_low_set_gpe() with the second argument
equal to ACPI_GPE_CONDITIONAL_ENABLE, is executed in parallel with
one of these functions, it may reverse changes made by them.
To fix the problem, introduce a new enable_mask field in struct
acpi_gpe_register_info in which to store the current mask of
enabled GPEs and modify acpi_hw_low_set_gpe() to take this
mask into account instead of enable_for_run when its second
argument is equal to ACPI_GPE_CONDITIONAL_ENABLE. Also modify
the low-level routines called by acpi_hw_disable_all_gpes(),
acpi_enable_all_wakeup_gpes() and acpi_enable_all_runtime_gpes()
to update the enable_mask masks of GPE registers after all
(successful) writes to those registers.
Acked-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/hwgpe.c')
-rw-r--r-- | drivers/acpi/acpica/hwgpe.c | 53 |
1 files changed, 43 insertions, 10 deletions
diff --git a/drivers/acpi/acpica/hwgpe.c b/drivers/acpi/acpica/hwgpe.c index 48ac7b7b59cd..494027f5c067 100644 --- a/drivers/acpi/acpica/hwgpe.c +++ b/drivers/acpi/acpica/hwgpe.c @@ -115,12 +115,12 @@ acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action) /* Set or clear just the bit that corresponds to this GPE */ register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info); - switch (action) { + switch (action & ~ACPI_GPE_SAVE_MASK) { case ACPI_GPE_CONDITIONAL_ENABLE: - /* Only enable if the enable_for_run bit is set */ + /* Only enable if the corresponding enable_mask bit is set */ - if (!(register_bit & gpe_register_info->enable_for_run)) { + if (!(register_bit & gpe_register_info->enable_mask)) { return (AE_BAD_PARAMETER); } @@ -145,6 +145,9 @@ acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action) /* Write the updated enable mask */ status = acpi_hw_write(enable_mask, &gpe_register_info->enable_address); + if (ACPI_SUCCESS(status) && (action & ACPI_GPE_SAVE_MASK)) { + gpe_register_info->enable_mask = enable_mask; + } return (status); } @@ -262,6 +265,32 @@ acpi_hw_get_gpe_status(struct acpi_gpe_event_info * gpe_event_info, /****************************************************************************** * + * FUNCTION: acpi_hw_gpe_enable_write + * + * PARAMETERS: enable_mask - Bit mask to write to the GPE register + * gpe_register_info - Gpe Register info + * + * RETURN: Status + * + * DESCRIPTION: Write the enable mask byte to the given GPE register. + * + ******************************************************************************/ + +static acpi_status +acpi_hw_gpe_enable_write(u8 enable_mask, + struct acpi_gpe_register_info *gpe_register_info) +{ + acpi_status status; + + status = acpi_hw_write(enable_mask, &gpe_register_info->enable_address); + if (ACPI_SUCCESS(status)) { + gpe_register_info->enable_mask = enable_mask; + } + return (status); +} + +/****************************************************************************** + * * FUNCTION: acpi_hw_disable_gpe_block * * PARAMETERS: gpe_xrupt_info - GPE Interrupt info @@ -287,8 +316,8 @@ acpi_hw_disable_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, /* Disable all GPEs in this register */ status = - acpi_hw_write(0x00, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(0x00, + &gpe_block->register_info[i]); if (ACPI_FAILURE(status)) { return (status); } @@ -355,21 +384,23 @@ acpi_hw_enable_runtime_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, { u32 i; acpi_status status; + struct acpi_gpe_register_info *gpe_register_info; /* NOTE: assumes that all GPEs are currently disabled */ /* Examine each GPE Register within the block */ for (i = 0; i < gpe_block->register_count; i++) { - if (!gpe_block->register_info[i].enable_for_run) { + gpe_register_info = &gpe_block->register_info[i]; + if (!gpe_register_info->enable_for_run) { continue; } /* Enable all "runtime" GPEs in this register */ status = - acpi_hw_write(gpe_block->register_info[i].enable_for_run, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(gpe_register_info->enable_for_run, + gpe_register_info); if (ACPI_FAILURE(status)) { return (status); } @@ -399,10 +430,12 @@ acpi_hw_enable_wakeup_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, { u32 i; acpi_status status; + struct acpi_gpe_register_info *gpe_register_info; /* Examine each GPE Register within the block */ for (i = 0; i < gpe_block->register_count; i++) { + gpe_register_info = &gpe_block->register_info[i]; /* * Enable all "wake" GPEs in this register and disable the @@ -410,8 +443,8 @@ acpi_hw_enable_wakeup_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, */ status = - acpi_hw_write(gpe_block->register_info[i].enable_for_wake, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(gpe_register_info->enable_for_wake, + gpe_register_info); if (ACPI_FAILURE(status)) { return (status); } |