iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ARM: OMAP3: Fix external abort on 36xx waking from off mode idle

Browse Source 
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 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.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Dave Gerlach 2016-04-13 20:49:48 -05:00 committed by Tony Lindgren
parent a1def45365
commit 1560d15861
1 changed files with 13 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
arch/arm/mach-omap2/pm34xx.c
View File

@ -198,7 +198,6 @@ 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);
@ -278,16 +277,20 @@ 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_sram_restore_context();
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_sram_restore_context();
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);