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| author | Achin Gupta <achin.gupta@arm.com> | 2014-05-09 19:32:25 +0100 |
|---|---|---|
| committer | Achin Gupta <achin.gupta@arm.com> | 2014-05-12 18:13:54 +0100 |
| commit | 317ba09021b90ef50c13a1c44b4d2091736b6a86 (patch) | |
| tree | 58622c4d74efcf77b11eb92178285a135a233620 /services/std_svc/psci/psci_entry.S | |
| parent | 60bc4bbd0bf705f30327e3c37973bcf1e1851110 (diff) | |
Fix broken standby state implementation in PSCI
This patch fixes the broken support for entry into standby states
introduced under commit-id 'd118f9f864' (tf-issues#94). Upon exit from
the platform defined standby state instead of returning to the caller
of the SMC, execution would get stuck in the wfi instruction meant for
entering a power down state. This patch ensures that exit from a
standby state and entry into a power down state do not interfere with
each other.
Fixes ARM-software/tf-issues#154
Change-Id: I56e5df353368e44d6eefc94ffedefe21929f5cfe
Diffstat (limited to 'services/std_svc/psci/psci_entry.S')
| -rw-r--r-- | services/std_svc/psci/psci_entry.S | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/services/std_svc/psci/psci_entry.S b/services/std_svc/psci/psci_entry.S index 256c538d..3d0181a8 100644 --- a/services/std_svc/psci/psci_entry.S +++ b/services/std_svc/psci/psci_entry.S @@ -37,6 +37,7 @@ .globl psci_aff_suspend_finish_entry .globl __psci_cpu_off .globl __psci_cpu_suspend + .globl psci_power_down_wfi /* ----------------------------------------------------- * This cpu has been physically powered up. Depending @@ -120,9 +121,6 @@ func __psci_cpu_off mrs x0, mpidr_el1 bl platform_set_coherent_stack bl psci_cpu_off - mov x1, #PSCI_E_SUCCESS - cmp x0, x1 - b.eq final_wfi mov sp, x19 ldp x19, x20, [sp,#0] add sp, sp, #0x10 @@ -144,9 +142,6 @@ func __psci_cpu_suspend mov x1, x21 mov x2, x22 bl psci_cpu_suspend - mov x1, #PSCI_E_SUCCESS - cmp x0, x1 - b.eq final_wfi mov sp, x19 ldp x21, x22, [sp,#0x10] ldp x19, x20, [sp,#0] @@ -154,7 +149,16 @@ func __psci_cpu_suspend func_epilogue ret -func final_wfi + /* -------------------------------------------- + * This function is called to indicate to the + * power controller that it is safe to power + * down this cpu. It should not exit the wfi + * and will be released from reset upon power + * up. 'wfi_spill' is used to catch erroneous + * exits from wfi. + * -------------------------------------------- + */ +func psci_power_down_wfi dsb sy // ensure write buffer empty wfi wfi_spill: |