linux-kernel - [PATCH 1/2] interconnect: Do not skip aggregation for disabled paths

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Date:   Thu, 23 Jul 2020 11:37:34 +0300
From:   Georgi Djakov <georgi.djakov@...aro.org>
To:     gregkh@...uxfoundation.org
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        georgi.djakov@...aro.org, Atul Dhudase <adhudase@...eaurora.org>,
        Sibi Sankar <sibis@...eaurora.org>
Subject: [PATCH 1/2] interconnect: Do not skip aggregation for disabled paths

When an interconnect path is being disabled, currently we don't aggregate
the requests for it afterwards. But the re-aggregation step shouldn't be
skipped, as it may leave the nodes with outdated bandwidth data. This
outdated data may actually keep the path still enabled and prevent the
device from going into lower power states.

Reported-by: Atul Dhudase <adhudase@...eaurora.org>
Fixes: 7d374b209083 ("interconnect: Add helpers for enabling/disabling a path")
Reviewed-by: Sibi Sankar <sibis@...eaurora.org>
Tested-by: Atul Dhudase <adhudase@...eaurora.org>
Reviewed-by: Atul Dhudase <adhudase@...eaurora.org>
Link: https://lore.kernel.org/r/20200721120740.3436-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@...aro.org>
---
 drivers/interconnect/core.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index e5f998744501..9e1ab701785c 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -243,6 +243,7 @@ static int aggregate_requests(struct icc_node *node)
 {
 	struct icc_provider *p = node->provider;
 	struct icc_req *r;
+	u32 avg_bw, peak_bw;
 
 	node->avg_bw = 0;
 	node->peak_bw = 0;
@@ -251,9 +252,14 @@ static int aggregate_requests(struct icc_node *node)
 		p->pre_aggregate(node);
 
 	hlist_for_each_entry(r, &node->req_list, req_node) {
-		if (!r->enabled)
-			continue;
-		p->aggregate(node, r->tag, r->avg_bw, r->peak_bw,
+		if (r->enabled) {
+			avg_bw = r->avg_bw;
+			peak_bw = r->peak_bw;
+		} else {
+			avg_bw = 0;
+			peak_bw = 0;
+		}
+		p->aggregate(node, r->tag, avg_bw, peak_bw,
 			     &node->avg_bw, &node->peak_bw);
 	}