| Message ID | 74514118.QN1Ey1fWSL@kreacher (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | PM / ACPI: sleep: Additional changes related to suspend-to-idle | expand |
Hi Rafael, On 2019-08-02 12:45, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > According to Section 3.5 of the "Intel Low Power S0 Idle" document [1], > Function 5 of the LPS0 _DSM is expected to be invoked when the system > configuration matches the criteria for entering the target low-power > state of the platform. In particular, this means that all devices > should be suspended and in low-power states already when that function > is invoked. > > This is not the case currently, however, because Function 5 of the > LPS0 _DSM is invoked by it before the "noirq" phase of device suspend, > which means that some devices may not have been put into low-power > states yet at that point. That is a consequence of the previous > design of the suspend-to-idle flow that allowed the "noirq" phase of > device suspend and the "noirq" phase of device resume to be carried > out for multiple times while "suspended" (if any spurious wakeup > events were detected) and the point of the LPS0 _DSM Function 5 > invocation was chosen so as to call it (and LPS0 _DSM Function 6 > analogously) once per suspend-resume cycle (regardless of how many > times the "noirq" phases of device suspend and resume were carried > out while "suspended"). > > Now that the suspend-to-idle flow has been redesigned to carry out > the "noirq" phases of device suspend and resume once in each cycle, > the code can be reordered to follow the specification that it is > based on more closely. > > For this purpose, add ->prepare_late and ->restore_early platform > callbacks for suspend-to-idle, to be executed, respectively, after > the "noirq" phase of suspending devices and before the "noirq" > phase of resuming them and make ACPI use them for the invocation > of LPS0 _DSM functions as appropriate. > > While at it, move the LPS0 entry requirements check to be made > before invoking Functions 3 and 5 of the LPS0 _DSM (also once > per cycle) as follows from the specification [1]. > > Link: https://uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf # [1] > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > In v2 this was patch 2. > > --- > drivers/acpi/sleep.c | 36 ++++++++++++++++++++++++------------ > include/linux/suspend.h | 2 ++ > kernel/power/suspend.c | 12 +++++++++--- > 3 files changed, 35 insertions(+), 15 deletions(-) > > Index: linux-pm/drivers/acpi/sleep.c > =================================================================== > --- linux-pm.orig/drivers/acpi/sleep.c > +++ linux-pm/drivers/acpi/sleep.c > @@ -954,11 +954,6 @@ static int acpi_s2idle_begin(void) > > static int acpi_s2idle_prepare(void) > { > - if (lps0_device_handle && !sleep_no_lps0) { > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); > - } > - > if (acpi_sci_irq_valid()) > enable_irq_wake(acpi_sci_irq); > > @@ -972,11 +967,22 @@ static int acpi_s2idle_prepare(void) > return 0; > } > > -static void acpi_s2idle_wake(void) > +static int acpi_s2idle_prepare_late(void) > { > - if (lps0_device_handle && !sleep_no_lps0 && pm_debug_messages_on) > + if (!lps0_device_handle || sleep_no_lps0) > + return 0; > + > + if (pm_debug_messages_on) > lpi_check_constraints(); > > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); > + > + return 0; > +} > + > +static void acpi_s2idle_wake(void) > +{ > /* > * If IRQD_WAKEUP_ARMED is set for the SCI at this point, the SCI has > * not triggered while suspended, so bail out. > @@ -1011,6 +1017,15 @@ static void acpi_s2idle_wake(void) > rearm_wake_irq(acpi_sci_irq); > } > > +static void acpi_s2idle_restore_early(void) > +{ > + if (!lps0_device_handle || sleep_no_lps0) > + return; > + > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); > +} > + > static void acpi_s2idle_restore(void) > { > s2idle_wakeup = false; > @@ -1021,11 +1036,6 @@ static void acpi_s2idle_restore(void) > > if (acpi_sci_irq_valid()) > disable_irq_wake(acpi_sci_irq); > - > - if (lps0_device_handle && !sleep_no_lps0) { > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); > - } > } > > static void acpi_s2idle_end(void) > @@ -1036,7 +1046,9 @@ static void acpi_s2idle_end(void) > static const struct platform_s2idle_ops acpi_s2idle_ops = { > .begin = acpi_s2idle_begin, > .prepare = acpi_s2idle_prepare, > + .prepare_late = acpi_s2idle_prepare_late, > .wake = acpi_s2idle_wake, > + .restore_early = acpi_s2idle_restore_early, > .restore = acpi_s2idle_restore, > .end = acpi_s2idle_end, > }; > Index: linux-pm/kernel/power/suspend.c > =================================================================== > --- linux-pm.orig/kernel/power/suspend.c > +++ linux-pm/kernel/power/suspend.c > @@ -253,13 +253,19 @@ static int platform_suspend_prepare_late > > static int platform_suspend_prepare_noirq(suspend_state_t state) > { > - return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ? > - suspend_ops->prepare_late() : 0; > + if (state == PM_SUSPEND_TO_IDLE) { > + if (s2idle_ops && s2idle_ops->prepare_late) > + return s2idle_ops->prepare_late(); > + } > + return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0; This unconditionally references suspend_ops here, what wasn't done earlier. On one of my test boards (OdroidXU) it causes following NULL pointer dereference since Linux next-20190809 (the first -next, which contains this patch): root@target:~# time rtcwake -s10 -mmem rtcwake: wakeup from "mem" using /dev/rtc0 at Fri Aug 9 12:21:43 2019 PM: suspend entry (s2idle) Filesystems sync: 0.001 seconds Freezing user space processes ... (elapsed 0.002 seconds) done. OOM killer disabled. Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. smsc95xx 1-2:1.0 eth0: entering SUSPEND2 mode wake enabled for irq 111 usb3503 4-0008: switched to STANDBY mode samsung-pinctrl 13400000.pinctrl: No retention data configured bank with external wakeup interrupt. Wake-up mask will not be set. 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000c pgd = ac9cf656 [0000000c] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 2027 Comm: rtcwake Not tainted 5.3.0-rc3-next-20190809 #6373 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) PC is at suspend_devices_and_enter+0x330/0xf2c LR is at lock_is_held_type+0x80/0x108 pc : [<c0195b78>] lr : [<c01883dc>] psr: 60000013 sp : e73dfe20 ip : 00000001 fp : 00000001 r10: c10b9394 r9 : c10ce36c r8 : c1007648 r7 : c16d26c8 r6 : 00000001 r5 : 00000000 r4 : c16d26dc r3 : 00000000 r2 : 00000000 r1 : c1014220 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 671ac06a DAC: 00000051 Process rtcwake (pid: 2027, stack limit = 0x59af371a) Stack: (0xe73dfe20 to 0xe73e0000) ... [<c0195b78>] (suspend_devices_and_enter) from [<c0196d0c>] (pm_suspend+0x598/0xcb8) [<c0196d0c>] (pm_suspend) from [<c0194848>] (state_store+0x6c/0xc8) [<c0194848>] (state_store) from [<c0330100>] (kernfs_fop_write+0x100/0x1e0) [<c0330100>] (kernfs_fop_write) from [<c02a1594>] (__vfs_write+0x30/0x1d0) [<c02a1594>] (__vfs_write) from [<c02a4090>] (vfs_write+0xa4/0x180) [<c02a4090>] (vfs_write) from [<c02a42f0>] (ksys_write+0x60/0xdc) [<c02a42f0>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xe73dffa8 to 0xe73dfff0) ... ---[ end trace 627069b7dfd482c9 ]--- > } > > static void platform_resume_noirq(suspend_state_t state) > { > - if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake) > + if (state == PM_SUSPEND_TO_IDLE) { > + if (s2idle_ops && s2idle_ops->restore_early) > + s2idle_ops->restore_early(); > + } else if (suspend_ops->wake) > suspend_ops->wake(); > } > > Index: linux-pm/include/linux/suspend.h > =================================================================== > --- linux-pm.orig/include/linux/suspend.h > +++ linux-pm/include/linux/suspend.h > @@ -190,7 +190,9 @@ struct platform_suspend_ops { > struct platform_s2idle_ops { > int (*begin)(void); > int (*prepare)(void); > + int (*prepare_late)(void); > void (*wake)(void); > + void (*restore_early)(void); > void (*restore)(void); > void (*end)(void); > }; Best regards
On Fri, Aug 9, 2019 at 2:00 PM Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > Hi Rafael, > > On 2019-08-02 12:45, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > According to Section 3.5 of the "Intel Low Power S0 Idle" document [1], > > Function 5 of the LPS0 _DSM is expected to be invoked when the system > > configuration matches the criteria for entering the target low-power > > state of the platform. In particular, this means that all devices > > should be suspended and in low-power states already when that function > > is invoked. > > > > This is not the case currently, however, because Function 5 of the > > LPS0 _DSM is invoked by it before the "noirq" phase of device suspend, > > which means that some devices may not have been put into low-power > > states yet at that point. That is a consequence of the previous > > design of the suspend-to-idle flow that allowed the "noirq" phase of > > device suspend and the "noirq" phase of device resume to be carried > > out for multiple times while "suspended" (if any spurious wakeup > > events were detected) and the point of the LPS0 _DSM Function 5 > > invocation was chosen so as to call it (and LPS0 _DSM Function 6 > > analogously) once per suspend-resume cycle (regardless of how many > > times the "noirq" phases of device suspend and resume were carried > > out while "suspended"). > > > > Now that the suspend-to-idle flow has been redesigned to carry out > > the "noirq" phases of device suspend and resume once in each cycle, > > the code can be reordered to follow the specification that it is > > based on more closely. > > > > For this purpose, add ->prepare_late and ->restore_early platform > > callbacks for suspend-to-idle, to be executed, respectively, after > > the "noirq" phase of suspending devices and before the "noirq" > > phase of resuming them and make ACPI use them for the invocation > > of LPS0 _DSM functions as appropriate. > > > > While at it, move the LPS0 entry requirements check to be made > > before invoking Functions 3 and 5 of the LPS0 _DSM (also once > > per cycle) as follows from the specification [1]. > > > > Link: https://uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf # [1] > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > --- > > > > In v2 this was patch 2. > > > > --- > > drivers/acpi/sleep.c | 36 ++++++++++++++++++++++++------------ > > include/linux/suspend.h | 2 ++ > > kernel/power/suspend.c | 12 +++++++++--- > > 3 files changed, 35 insertions(+), 15 deletions(-) > > > > Index: linux-pm/drivers/acpi/sleep.c > > =================================================================== > > --- linux-pm.orig/drivers/acpi/sleep.c > > +++ linux-pm/drivers/acpi/sleep.c > > @@ -954,11 +954,6 @@ static int acpi_s2idle_begin(void) > > > > static int acpi_s2idle_prepare(void) > > { > > - if (lps0_device_handle && !sleep_no_lps0) { > > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); > > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); > > - } > > - > > if (acpi_sci_irq_valid()) > > enable_irq_wake(acpi_sci_irq); > > > > @@ -972,11 +967,22 @@ static int acpi_s2idle_prepare(void) > > return 0; > > } > > > > -static void acpi_s2idle_wake(void) > > +static int acpi_s2idle_prepare_late(void) > > { > > - if (lps0_device_handle && !sleep_no_lps0 && pm_debug_messages_on) > > + if (!lps0_device_handle || sleep_no_lps0) > > + return 0; > > + > > + if (pm_debug_messages_on) > > lpi_check_constraints(); > > > > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); > > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); > > + > > + return 0; > > +} > > + > > +static void acpi_s2idle_wake(void) > > +{ > > /* > > * If IRQD_WAKEUP_ARMED is set for the SCI at this point, the SCI has > > * not triggered while suspended, so bail out. > > @@ -1011,6 +1017,15 @@ static void acpi_s2idle_wake(void) > > rearm_wake_irq(acpi_sci_irq); > > } > > > > +static void acpi_s2idle_restore_early(void) > > +{ > > + if (!lps0_device_handle || sleep_no_lps0) > > + return; > > + > > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); > > + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); > > +} > > + > > static void acpi_s2idle_restore(void) > > { > > s2idle_wakeup = false; > > @@ -1021,11 +1036,6 @@ static void acpi_s2idle_restore(void) > > > > if (acpi_sci_irq_valid()) > > disable_irq_wake(acpi_sci_irq); > > - > > - if (lps0_device_handle && !sleep_no_lps0) { > > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); > > - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); > > - } > > } > > > > static void acpi_s2idle_end(void) > > @@ -1036,7 +1046,9 @@ static void acpi_s2idle_end(void) > > static const struct platform_s2idle_ops acpi_s2idle_ops = { > > .begin = acpi_s2idle_begin, > > .prepare = acpi_s2idle_prepare, > > + .prepare_late = acpi_s2idle_prepare_late, > > .wake = acpi_s2idle_wake, > > + .restore_early = acpi_s2idle_restore_early, > > .restore = acpi_s2idle_restore, > > .end = acpi_s2idle_end, > > }; > > Index: linux-pm/kernel/power/suspend.c > > =================================================================== > > --- linux-pm.orig/kernel/power/suspend.c > > +++ linux-pm/kernel/power/suspend.c > > @@ -253,13 +253,19 @@ static int platform_suspend_prepare_late > > > > static int platform_suspend_prepare_noirq(suspend_state_t state) > > { > > - return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ? > > - suspend_ops->prepare_late() : 0; > > + if (state == PM_SUSPEND_TO_IDLE) { > > + if (s2idle_ops && s2idle_ops->prepare_late) > > + return s2idle_ops->prepare_late(); This should be return s2idle_ops && s2idle_ops->prepare_late ? s2idle_ops->prepare_late() : 0; > > + } > > + return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0; > > This unconditionally references suspend_ops here, what wasn't done > earlier. On one of my test boards (OdroidXU) it causes following NULL > pointer dereference since Linux next-20190809 (the first -next, which > contains this patch): Sorry about this, will fix early next week.
Index: linux-pm/drivers/acpi/sleep.c =================================================================== --- linux-pm.orig/drivers/acpi/sleep.c +++ linux-pm/drivers/acpi/sleep.c @@ -954,11 +954,6 @@ static int acpi_s2idle_begin(void) static int acpi_s2idle_prepare(void) { - if (lps0_device_handle && !sleep_no_lps0) { - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); - acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); - } - if (acpi_sci_irq_valid()) enable_irq_wake(acpi_sci_irq); @@ -972,11 +967,22 @@ static int acpi_s2idle_prepare(void) return 0; } -static void acpi_s2idle_wake(void) +static int acpi_s2idle_prepare_late(void) { - if (lps0_device_handle && !sleep_no_lps0 && pm_debug_messages_on) + if (!lps0_device_handle || sleep_no_lps0) + return 0; + + if (pm_debug_messages_on) lpi_check_constraints(); + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF); + acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY); + + return 0; +} + +static void acpi_s2idle_wake(void) +{ /* * If IRQD_WAKEUP_ARMED is set for the SCI at this point, the SCI has * not triggered while suspended, so bail out. @@ -1011,6 +1017,15 @@ static void acpi_s2idle_wake(void) rearm_wake_irq(acpi_sci_irq); } +static void acpi_s2idle_restore_early(void) +{ + if (!lps0_device_handle || sleep_no_lps0) + return; + + acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); + acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); +} + static void acpi_s2idle_restore(void) { s2idle_wakeup = false; @@ -1021,11 +1036,6 @@ static void acpi_s2idle_restore(void) if (acpi_sci_irq_valid()) disable_irq_wake(acpi_sci_irq); - - if (lps0_device_handle && !sleep_no_lps0) { - acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT); - acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON); - } } static void acpi_s2idle_end(void) @@ -1036,7 +1046,9 @@ static void acpi_s2idle_end(void) static const struct platform_s2idle_ops acpi_s2idle_ops = { .begin = acpi_s2idle_begin, .prepare = acpi_s2idle_prepare, + .prepare_late = acpi_s2idle_prepare_late, .wake = acpi_s2idle_wake, + .restore_early = acpi_s2idle_restore_early, .restore = acpi_s2idle_restore, .end = acpi_s2idle_end, }; Index: linux-pm/kernel/power/suspend.c =================================================================== --- linux-pm.orig/kernel/power/suspend.c +++ linux-pm/kernel/power/suspend.c @@ -253,13 +253,19 @@ static int platform_suspend_prepare_late static int platform_suspend_prepare_noirq(suspend_state_t state) { - return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ? - suspend_ops->prepare_late() : 0; + if (state == PM_SUSPEND_TO_IDLE) { + if (s2idle_ops && s2idle_ops->prepare_late) + return s2idle_ops->prepare_late(); + } + return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0; } static void platform_resume_noirq(suspend_state_t state) { - if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake) + if (state == PM_SUSPEND_TO_IDLE) { + if (s2idle_ops && s2idle_ops->restore_early) + s2idle_ops->restore_early(); + } else if (suspend_ops->wake) suspend_ops->wake(); } Index: linux-pm/include/linux/suspend.h =================================================================== --- linux-pm.orig/include/linux/suspend.h +++ linux-pm/include/linux/suspend.h @@ -190,7 +190,9 @@ struct platform_suspend_ops { struct platform_s2idle_ops { int (*begin)(void); int (*prepare)(void); + int (*prepare_late)(void); void (*wake)(void); + void (*restore_early)(void); void (*restore)(void); void (*end)(void); };