[Skiboot] [PATCH] occ: Set up OCC messaging even if we fail to setup pstates

[Stewart Smith]

This means that we no longer hit this bug if we fail to get valid pstates
from the OCC.

[console-pexpect]#echo 1 > //sys/firmware/opal/sensor_groups//occ-csm0/clear
echo 1 > //sys/firmware/opal/sensor_groups//occ-csm0/clear
[   94.019971181,5] CPU ATTEMPT TO RE-ENTER FIRMWARE! PIR=083d cpu @0x33cf4000 -> pir=083d token=8
[   94.020098392,5] CPU ATTEMPT TO RE-ENTER FIRMWARE! PIR=083d cpu @0x33cf4000 -> pir=083d token=8
[   10.318805] Disabling lock debugging due to kernel taint
[   10.318808] Severe Machine check interrupt [Not recovered]
[   10.318812]   NIP [000000003003e434]: 0x3003e434
[   10.318813]   Initiator: CPU
[   10.318815]   Error type: Real address [Load/Store (foreign)]
[   10.318817] opal: Hardware platform error: Unrecoverable Machine Check exception
[   10.318821] CPU: 117 PID: 2745 Comm: sh Tainted: G   M             4.15.9-openpower1 #3
[   10.318823] NIP:  000000003003e434 LR: 000000003003025c CTR: 0000000030030240
[   10.318825] REGS: c00000003fa7bd80 TRAP: 0200   Tainted: G   M              (4.15.9-openpower1)
[   10.318826] MSR:  9000000000201002 <SF,HV,ME,RI>  CR: 48002888  XER: 20040000
[   10.318831] CFAR: 0000000030030258 DAR: 394a00147d5a03a6 DSISR: 00000008 SOFTE: 1

Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
---
 hw/occ.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/hw/occ.c b/hw/occ.c
index 37cf73c30bbd..90d3105eb1a8 100644
--- a/hw/occ.c
+++ b/hw/occ.c
@@ -1365,6 +1365,9 @@ int occ_set_powercap(u32 handle, int token, u32 pcap)
 	if (powercap_get_attr(handle) != POWERCAP_OCC_CUR)
 		return OPAL_PERMISSION;
 
+	if (!chips)
+		return OPAL_HARDWARE;
+
 	for (i = 0; i < nr_occs; i++)
 		if (chips[i].occ_role == OCC_ROLE_MASTER)
 			break;
@@ -1721,14 +1724,11 @@ void occ_pstates_init(void)
 	if (!add_cpu_pstate_properties(&pstate_nom)) {
 		log_simple_error(&e_info(OPAL_RC_OCC_PSTATE_INIT),
 			"Skiping core cpufreq init due to OCC error\n");
-		return;
-	}
-
-	/*
-	 * Setup host based pstates and set nominal frequency only in
-	 * P8.
-	 */
-	if (proc_gen == proc_gen_p8) {
+	} else if (proc_gen == proc_gen_p8) {
+		/*
+		 * Setup host based pstates and set nominal frequency only in
+		 * P8.
+		 */
 		for_each_chip(chip)
 			for_each_available_core_in_chip(c, chip->id)
 				cpu_pstates_prepare_core(chip, c, pstate_nom);
-- 
2.14.3