From fc45e55ebc58dbf622cb89ddbf797589c7a5510b Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Thu, 21 Apr 2022 16:36:34 +0300 Subject: ACPI: processor: idle: Avoid falling back to C3 type C-states MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The "safe state" index is used by acpi_idle_enter_bm() to avoid entering a C-state that may require bus mastering to be disabled on entry in the cases when this is not going to happen. For this reason, it should not be set to point to C3 type of C-states, because they may require bus mastering to be disabled on entry in principle. This was broken by commit d6b88ce2eb9d ("ACPI: processor idle: Allow playing dead in C3 state") which inadvertently allowed the "safe state" index to point to C3 type of C-states. This results in a machine that won't boot past the point when it first enters C3. Restore the correct behaviour (either demote to C1/C2, or use C3 but also set ARB_DIS=1). I hit this on a Fujitsu Siemens Lifebook S6010 (P3) machine. Fixes: d6b88ce2eb9d ("ACPI: processor idle: Allow playing dead in C3 state") Cc: 5.16+ # 5.16+ Signed-off-by: Ville Syrjälä Tested-by: Woody Suwalski [ rjw: Subject and changelog adjustments ] Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 4556c86c3465..5f296e099bce 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -795,7 +795,8 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) { state->enter_dead = acpi_idle_play_dead; - drv->safe_state_index = count; + if (cx->type != ACPI_STATE_C3) + drv->safe_state_index = count; } /* * Halt-induced C1 is not good for ->enter_s2idle, because it -- cgit v1.2.3-58-ga151 From 20e582e16af24b074e583f9551fad557882a3c9d Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Wed, 20 Apr 2022 16:44:17 +0300 Subject: Revert "ACPI: processor: idle: fix lockup regression on 32-bit ThinkPad T40" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This reverts commit bfe55a1f7fd6bfede16078bf04c6250fbca11588. This was presumably misdiagnosed as an inability to use C3 at all when I suspect the real problem is just misconfiguration of C3 vs. ARB_DIS. Signed-off-by: Ville Syrjälä Cc: 5.16+ # 5.16+ Tested-by: Woody Suwalski Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 5f296e099bce..eb95e188d62b 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -96,11 +96,6 @@ static const struct dmi_system_id processor_power_dmi_table[] = { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, (void *)1}, - /* T40 can not handle C3 idle state */ - { set_max_cstate, "IBM ThinkPad T40", { - DMI_MATCH(DMI_SYS_VENDOR, "IBM"), - DMI_MATCH(DMI_PRODUCT_NAME, "23737CU")}, - (void *)2}, {}, }; -- cgit v1.2.3-58-ga151