From b127cdb879aed2ced388af3cd9481e80c68f3e8c Mon Sep 17 00:00:00 2001 From: Achin Gupta Date: Tue, 12 Nov 2013 16:40:00 +0000 Subject: clear wakeup enable bit upon resuming from suspend The FVP specific code that gets called after a cpu has been physically powered on after having been turned off or suspended earlier does not clear the PWRC.PWKUPR.WEN bit. Not doing so causes problems if: a cpu is suspended, woken from suspend, powered down through a cpu_off call & receives a spurious interrupt. Since the WEN bit is not cleared after the cpu woke up from suspend, the spurious wakeup will power the cpu on. Since the cpu_off call clears the jump address in the mailbox this spurious wakeup will cause the cpu to crash. This patch fixes this issue by clearing the WEN bit whenever a cpu is powered up. Change-Id: Ic91f5dffe1ed01d76bc7fc807acf0ecd3e38ce5b --- plat/fvp/fvp_pm.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'plat') diff --git a/plat/fvp/fvp_pm.c b/plat/fvp/fvp_pm.c index fd92526d..658a2859 100644 --- a/plat/fvp/fvp_pm.c +++ b/plat/fvp/fvp_pm.c @@ -251,7 +251,7 @@ int fvp_affinst_suspend(unsigned long mpidr, * Program the power controller to power this * cpu off and enable wakeup interrupts. */ - fvp_pwrc_write_pwkupr(mpidr); + fvp_pwrc_set_wen(mpidr); fvp_pwrc_write_ppoffr(mpidr); } break; @@ -309,6 +309,12 @@ int fvp_affinst_on_finish(unsigned long mpidr, write_cpuectlr(ectlr); } + /* + * Clear PWKUPR.WEN bit to ensure interrupts do not interfere + * with a cpu power down unless the bit is set again + */ + fvp_pwrc_clr_wen(mpidr); + /* Zero the jump address in the mailbox for this cpu */ fvp_mboxes = (mailbox *) (TZDRAM_BASE + MBOX_OFF); linear_id = platform_get_core_pos(mpidr); -- cgit