From 7cef472ed1fea75cc63cb0d8ac86d6a13d08517d Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Mon, 27 Aug 2018 15:43:54 +0530 Subject: opal/hmi: Wakeup the cpu before reading core_fir When stop state 5 is enabled, reading the core_fir during an HMI can result in a xscom read error with xscom_read() returning an OPAL_XSCOM_PARTIAL_GOOD error code and core_fir value of all FFs. At present this return error code is not handled in decode_core_fir() hence the invalid core_fir value is sent to the kernel where it interprets it as a FATAL hmi causing a system check-stop. This can be prevented by forcing the core to wake-up using before reading the core_fir. Hence this patch wraps the call to read_core_fir() within calls to dctl_set_special_wakeup() and dctl_clear_special_wakeup(). Suggested-by: Michael Neuling Signed-off-by: Vaibhav Jain Signed-off-by: Mahesh J Salgaonkar Acked-by: Gautham R. Shenoy Reviewed-by: Shilpasri G Bhat Signed-off-by: Stewart Smith --- core/hmi.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/core/hmi.c b/core/hmi.c index 57f3fdb..c01a2c3 100644 --- a/core/hmi.c +++ b/core/hmi.c @@ -379,7 +379,7 @@ static bool decode_core_fir(struct cpu_thread *cpu, { uint64_t core_fir; uint32_t core_id; - int i; + int i, swkup_rc; bool found = false; int64_t ret; const char *loc; @@ -390,14 +390,19 @@ static bool decode_core_fir(struct cpu_thread *cpu, core_id = pir_to_core_id(cpu->pir); + /* Force the core to wakeup, otherwise reading core_fir is unrealiable + * if stop-state 5 is enabled. + */ + swkup_rc = dctl_set_special_wakeup(cpu); + /* Get CORE FIR register value. */ ret = read_core_fir(cpu->chip_id, core_id, &core_fir); - if (ret == OPAL_HARDWARE) { - prerror("XSCOM error reading CORE FIR\n"); - /* If the FIR can't be read, we should checkstop. */ - return true; - } else if (ret == OPAL_WRONG_STATE) { + if (!swkup_rc) + dctl_clear_special_wakeup(cpu); + + + if (ret == OPAL_WRONG_STATE) { /* * CPU is asleep, so it probably didn't cause the checkstop. * If no other HMI cause is found a "catchall" checkstop @@ -408,6 +413,10 @@ static bool decode_core_fir(struct cpu_thread *cpu, "FIR read failed, chip %d core %d asleep\n", cpu->chip_id, core_id); return false; + } else if (ret != OPAL_SUCCESS) { + prerror("XSCOM error reading CORE FIR\n"); + /* If the FIR can't be read, we should checkstop. */ + return true; } if (!core_fir) -- cgit v1.1