ARM: OMAP3: Fix external abort on 36xx waking from off mode idle
PATCH 1/1 ARM: OMAP3: Fix external abort on 36xx waking from off mode idle
Depending on timing during the resume path from off mode on 36xx, we may see external aborts. These seem to be caused by the following:
- OMAP3 Advisory 1.62 "MPU Cannot Exit from Standby" says we need to disable disable intc autoidle before WFI
- DM3730 Advisory 1.106 "MPU Leaves MSTANDBY State Before IDLEREQ of Interrupt Controller is Released" says we need to wait before accessing intc
omap3_intc_resume_idle restores the intc autoidle for all resume paths, however in the resume path from off mode only it is also being restored by omap_intc_restore_context before this call to omap3_intc_resume_idle happens. The second restore of the intc autoidle in this path is what appears to be causing the external abort so for the off mode resume path let's rely on omap_intc_restore_context to restore intc autoidle, and for all other paths let omap3_intc_resume_idle handle it as it is now.
--- arch/arm/mach-omap2/pm34xx.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
arch/arm/mach-omap2/pm34xx.c +14 -11
@@ -268,7 +268,6 @@ void omap_sram_idle(void)int per_next_state =PWRDM_POWER_ON ;int core_next_state =PWRDM_POWER_ON ;int per_going_off; -int core_prev_state;u32 sdrc_pwr =0 ; mpu_next_state =pwrdm_read_next_pwrst (mpu_pwrdm);
@@ -348,17 +347,21 @@ void omap_sram_idle(void)sdrc_write_reg (sdrc_pwr,SDRC_POWER );/* CORE */ -if (core_next_state <PWRDM_POWER_ON ) { - core_prev_state =pwrdm_read_prev_pwrst (core_pwrdm); -if (core_prev_state ==PWRDM_POWER_OFF ) { -omap3_core_restore_context (); -omap3_cm_restore_context (); -omap3_push_sram_idle (); -omap3_push_sram_secure_idle (); -omap2_sms_restore_context (); - } +if (core_next_state <PWRDM_POWER_ON && +pwrdm_read_prev_pwrst (core_pwrdm) ==PWRDM_POWER_OFF ) { +omap3_core_restore_context (); +omap3_cm_restore_context (); +omap3_push_sram_idle (); +omap3_push_sram_secure_idle (); +omap2_sms_restore_context (); + }else { +/* +* In off-mode resume path above, omap3_core_restore_context +* also handles the INTC autoidle restore done here so limit +* this to non-off mode resume paths so we don't do it twice. +*/ +omap3_intc_resume_idle (); } -omap3_intc_resume_idle ();pwrdm_post_transition (NULL );
Signature · 1 line
2.7.3
Tony Lindgren
maintainerPATCH 1/1 ARM: OMAP3: Fix external abort on 36xx waking from off mode idle
Quoted 31 lines · Dave Gerlach
arch/arm/mach-omap2/pm34xx.c +8
-10@@ -268,7 +268,6 @@ void omap_sram_idle(void)int per_next_state =PWRDM_POWER_ON ;int core_next_state =PWRDM_POWER_ON ;int per_going_off; -int core_prev_state;u32 sdrc_pwr =0 ; mpu_next_state =pwrdm_read_next_pwrst (mpu_pwrdm);@@ -348,17 +347,21 @@ void omap_sram_idle(void)sdrc_write_reg (sdrc_pwr,SDRC_POWER );/* CORE */ -if (core_next_state <PWRDM_POWER_ON ) { - core_prev_state =pwrdm_read_prev_pwrst (core_pwrdm); -if (core_prev_state ==PWRDM_POWER_OFF ) { -omap3_core_restore_context (); -omap3_cm_restore_context (); -omap3_push_sram_idle (); -omap3_push_sram_secure_idle (); -omap2_sms_restore_context (); - } +if (core_next_state <PWRDM_POWER_ON && +pwrdm_read_prev_pwrst (core_pwrdm) ==PWRDM_POWER_OFF ) { +omap3_core_restore_context (); +omap3_cm_restore_context (); +omap3_push_sram_idle (); +omap3_push_sram_secure_idle (); +omap2_sms_restore_context (); + }else {
arch/arm/mach-omap2/pm34xx.c void omap_sram_idle(void) · line 366
Quoted 10 lines
arch/arm/mach-omap2/pm34xx.c +6
-1+/* +* In off-mode resume path above, omap3_core_restore_context +* also handles the INTC autoidle restore done here so limit +* this to non-off mode resume paths so we don't do it twice. +*/ +omap3_intc_resume_idle (); } -omap3_intc_resume_idle ();pwrdm_post_transition (NULL );
Can you please repost against v4.7-rc? This does not apply as mainline still uses omap3_sram_restore_context(). Should be retested again with your patches applied on top of this fix.
Regards,
Tony
PATCH 1/1 ARM: OMAP3: Fix external abort on 36xx waking from off mode idle
Quoted 41 lines · Tony Lindgren
Quoted 40 lines · Dave Gerlach
arch/arm/mach-omap2/pm34xx.c +14
-11@@ -268,7 +268,6 @@ void omap_sram_idle(void)int per_next_state =PWRDM_POWER_ON ;int core_next_state =PWRDM_POWER_ON ;int per_going_off; -int core_prev_state;u32 sdrc_pwr =0 ; mpu_next_state =pwrdm_read_next_pwrst (mpu_pwrdm);@@ -348,17 +347,21 @@ void omap_sram_idle(void)sdrc_write_reg (sdrc_pwr,SDRC_POWER );/* CORE */ -if (core_next_state <PWRDM_POWER_ON ) { - core_prev_state =pwrdm_read_prev_pwrst (core_pwrdm); -if (core_prev_state ==PWRDM_POWER_OFF ) { -omap3_core_restore_context (); -omap3_cm_restore_context (); -omap3_push_sram_idle (); -omap3_push_sram_secure_idle (); -omap2_sms_restore_context (); - } +if (core_next_state <PWRDM_POWER_ON && +pwrdm_read_prev_pwrst (core_pwrdm) ==PWRDM_POWER_OFF ) { +omap3_core_restore_context (); +omap3_cm_restore_context (); +omap3_push_sram_idle (); +omap3_push_sram_secure_idle (); +omap2_sms_restore_context (); + }else { +/* +* In off-mode resume path above, omap3_core_restore_context +* also handles the INTC autoidle restore done here so limit +* this to non-off mode resume paths so we don't do it twice. +*/ +omap3_intc_resume_idle (); } -omap3_intc_resume_idle ();
Quoted 6 lines
arch/arm/mach-omap2/pm34xx.c void omap_sram_idle(void) · line 366
Quoted 1 line
arch/arm/mach-omap2/pm34xx.c +0
-0pwrdm_post_transition (NULL );Can you please repost against v4.7-rc? This does not apply as mainline still uses
omap3_sram_restore_context(). Should be retested again with your patches applied on top of this fix.
Whoops, complete oversight on my part, retested and reported here:
https://patchwork.kernel.org/patch/8830421/
Tests showed the exact same behavior, no abort with or without patch, with my sram series on top there was also no abort, but if I remove the fix patch the abort comes back.
Regards,
Dave
Quoted 4 lines
Regards,
Tony