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From: Mike Tipton <mdtipton@codeaurora.org>
To: georgi.djakov@linaro.org
Cc: bjorn.andersson@linaro.org, agross@kernel.org,
	linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Mike Tipton <mdtipton@codeaurora.org>
Subject: [PATCH v3 6/6] interconnect: qcom: Fix small BW votes being truncated to zero
Date: Fri, 31 Jul 2020 20:32:15 -0700
Message-ID: <20200801033215.1440-7-mdtipton@codeaurora.org> (raw)
In-Reply-To: <20200801033215.1440-1-mdtipton@codeaurora.org>

Small BW votes that translate to less than a single BCM unit are
currently truncated to zero. Ensure that non-zero BW requests always
result in at least a vote of 1 to BCM.

Fixes: 976daac4a1c5 ("interconnect: qcom: Consolidate interconnect RPMh support")
Signed-off-by: Mike Tipton <mdtipton@codeaurora.org>
---
 drivers/interconnect/qcom/bcm-voter.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
index be7660b95ccc..887d13721e52 100644
--- a/drivers/interconnect/qcom/bcm-voter.c
+++ b/drivers/interconnect/qcom/bcm-voter.c
@@ -54,8 +54,20 @@ static int cmp_vcd(void *priv, struct list_head *a, struct list_head *b)
 		return 1;
 }
 
+static u64 bcm_div(u64 num, u32 base)
+{
+	/* Ensure that small votes aren't lost. */
+	if (num && num < base)
+		return 1;
+
+	do_div(num, base);
+
+	return num;
+}
+
 static void bcm_aggregate(struct qcom_icc_bcm *bcm)
 {
+	struct qcom_icc_node *node;
 	size_t i, bucket;
 	u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
 	u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
@@ -63,22 +75,21 @@ static void bcm_aggregate(struct qcom_icc_bcm *bcm)
 
 	for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
 		for (i = 0; i < bcm->num_nodes; i++) {
-			temp = bcm->nodes[i]->sum_avg[bucket] * bcm->aux_data.width;
-			do_div(temp, bcm->nodes[i]->buswidth * bcm->nodes[i]->channels);
+			node = bcm->nodes[i];
+			temp = bcm_div(node->sum_avg[bucket] * bcm->aux_data.width,
+				       node->buswidth * node->channels);
 			agg_avg[bucket] = max(agg_avg[bucket], temp);
 
-			temp = bcm->nodes[i]->max_peak[bucket] * bcm->aux_data.width;
-			do_div(temp, bcm->nodes[i]->buswidth);
+			temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
+				       node->buswidth);
 			agg_peak[bucket] = max(agg_peak[bucket], temp);
 		}
 
 		temp = agg_avg[bucket] * bcm->vote_scale;
-		do_div(temp, bcm->aux_data.unit);
-		bcm->vote_x[bucket] = temp;
+		bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);
 
 		temp = agg_peak[bucket] * bcm->vote_scale;
-		do_div(temp, bcm->aux_data.unit);
-		bcm->vote_y[bucket] = temp;
+		bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
 	}
 
 	if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


      parent reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-01  3:32 [PATCH v3 0/6] interconnect: qcom: Misc bcm-voter changes and fixes Mike Tipton
2020-08-01  3:32 ` [PATCH v3 1/6] dt-bindings: interconnect: Add generic qcom bindings Mike Tipton
2020-08-01  3:32 ` [PATCH v3 2/6] dt-bindings: interconnect: Add property to set BCM TCS wait behavior Mike Tipton
2020-08-01  3:32 ` [PATCH v3 3/6] interconnect: qcom: Support bcm-voter-specific " Mike Tipton
2020-08-01  3:32 ` [PATCH v3 4/6] interconnect: qcom: Only wait for completion in AMC/WAKE by default Mike Tipton
2020-08-01  3:32 ` [PATCH v3 5/6] interconnect: qcom: Add support for per-BCM scaling factors Mike Tipton
2020-08-01  3:32 ` Mike Tipton [this message]

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