linux-kernel - [PATCH v6 2/3] soc: qcom: rpmh: Update dirty flag only when data changes

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Message-Id: <1582277527-19638-3-git-send-email-mkshah@codeaurora.org>
Date:   Fri, 21 Feb 2020 15:02:06 +0530
From:   Maulik Shah <mkshah@...eaurora.org>
To:     swboyd@...omium.org, mka@...omium.org, evgreen@...omium.org,
        bjorn.andersson@...aro.org
Cc:     linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        agross@...nel.org, dianders@...omium.org, rnayak@...eaurora.org,
        ilina@...eaurora.org, lsrao@...eaurora.org,
        Maulik Shah <mkshah@...eaurora.org>
Subject: [PATCH v6 2/3] soc: qcom: rpmh: Update dirty flag only when data changes

Currently rpmh ctrlr dirty flag is set for all cases regardless
of data is really changed or not. Add changes to update it when
data is updated to newer values.

Also move dirty flag updates to happen from within cache_lock.

Signed-off-by: Maulik Shah <mkshah@...eaurora.org>
---
 drivers/soc/qcom/rpmh.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index eb0ded0..83ba4e0 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -139,20 +139,27 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
 existing:
 	switch (state) {
 	case RPMH_ACTIVE_ONLY_STATE:
-		if (req->sleep_val != UINT_MAX)
+		if (req->sleep_val != UINT_MAX) {
 			req->wake_val = cmd->data;
+			ctrlr->dirty = true;
+		}
 		break;
 	case RPMH_WAKE_ONLY_STATE:
-		req->wake_val = cmd->data;
+		if (req->wake_val != cmd->data) {
+			req->wake_val = cmd->data;
+			ctrlr->dirty = true;
+		}
 		break;
 	case RPMH_SLEEP_STATE:
-		req->sleep_val = cmd->data;
+		if (req->sleep_val != cmd->data) {
+			req->sleep_val = cmd->data;
+			ctrlr->dirty = true;
+		}
 		break;
 	default:
 		break;
 	}
 
-	ctrlr->dirty = true;
 unlock:
 	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 
@@ -287,6 +294,7 @@ static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
 
 	spin_lock_irqsave(&ctrlr->cache_lock, flags);
 	list_add_tail(&req->list, &ctrlr->batch_cache);
+	ctrlr->dirty = true;
 	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 }
 
@@ -323,6 +331,7 @@ static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
 	list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
 		kfree(req);
 	INIT_LIST_HEAD(&ctrlr->batch_cache);
+	ctrlr->dirty = true;
 	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 }
 
@@ -456,6 +465,7 @@ static int send_single(struct rpmh_ctrlr *ctrlr, enum rpmh_state state,
 int rpmh_flush(struct rpmh_ctrlr *ctrlr)
 {
 	struct cache_req *p;
+	unsigned long flags;
 	int ret;
 
 	if (!ctrlr->dirty) {
@@ -488,7 +498,9 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
 			return ret;
 	}
 
+	spin_lock_irqsave(&ctrlr->cache_lock, flags);
 	ctrlr->dirty = false;
+	spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 
 	return 0;
 }
@@ -507,7 +519,6 @@ int rpmh_invalidate(const struct device *dev)
 	int ret;
 
 	invalidate_batch(ctrlr);
-	ctrlr->dirty = true;
 
 	do {
 		ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
-- 
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