From d665e102ef3760d590a35b9051a8941062e22df5 Mon Sep 17 00:00:00 2001 From: Robert Lippert Date: Mon, 20 Nov 2017 11:41:25 +0530 Subject: hw/dts: retry special wakeup operation if core still gated It has been observed that in some cases the special wakeup operation can "succeed" but the core is still in a gated/offline state. Check for this state after attempting to wakeup a core and retry the wakeup if necessary. Change-Id: Ia6b1b75dcab590c299bed3ee0a42031f09c39eda Signed-off-by: Robert Lippert Signed-off-by: Stewart Smith --- hw/dts.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) (limited to 'hw/dts.c') diff --git a/hw/dts.c b/hw/dts.c index 72a392b..d881f96 100644 --- a/hw/dts.c +++ b/hw/dts.c @@ -236,6 +236,34 @@ static int dts_read_core_temp_p9(uint32_t pir, struct dts *dts) return 0; } +static int dts_wakeup_core(struct cpu_thread *cpu) +{ + int retries = 10; + int rc; + + while (retries-- > 0) { + rc = dctl_set_special_wakeup(cpu); + if (rc) { + prerror("Failed to set special wakeup on %d (%d)\n", + cpu->pir, rc); + return rc; + } + + if (!dctl_core_is_gated(cpu)) + break; + + prlog(PR_NOTICE, "Retrying special wakeup on %d\n", cpu->pir); + rc = dctl_clear_special_wakeup(cpu); + if (rc) { + prerror("Failed to clear special wakeup on %d (%d)\n", + cpu->pir, rc); + return rc; + } + } + + return rc; +} + static void dts_async_read_temp(struct timer *t __unused, void *data, u64 now __unused) { @@ -243,7 +271,7 @@ static void dts_async_read_temp(struct timer *t __unused, void *data, int rc, swkup_rc; struct cpu_thread *cpu = data; - swkup_rc = dctl_set_special_wakeup(cpu); + swkup_rc = dts_wakeup_core(cpu); rc = dts_read_core_temp_p9(cpu->pir, &dts); if (!rc) { -- cgit v1.1