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From:   Claudiu <claudiu.beznea@tuxon.dev>
To:     geert+renesas@glider.be, mturquette@baylibre.com, sboyd@kernel.org,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
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        biju.das.jz@bp.renesas.com
Cc:     linux-renesas-soc@vger.kernel.org, linux-clk@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
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Subject: [PATCH v2 06/28] clk: renesas: rzg2l: remove critical area
Date:   Fri, 29 Sep 2023 08:38:53 +0300
Message-Id: <20230929053915.1530607-7-claudiu.beznea@bp.renesas.com>
In-Reply-To: <20230929053915.1530607-1-claudiu.beznea@bp.renesas.com>
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From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

spinlock in rzg2l_mod_clock_endisable() is intended to protect the accesses
to hardware register. There is no need to protect the instructions that set
temporary variable which will be then written to register. With this only
one write to one clock register is executed thus locking/unlocking rmw_lock
is removed.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v2:
- removed also the spinlock
- s/reduce/remove in patch title

 drivers/clk/renesas/rzg2l-cpg.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index f411e428196c..d936832e098f 100644
--- a/drivers/clk/renesas/rzg2l-cpg.c
+++ b/drivers/clk/renesas/rzg2l-cpg.c
@@ -895,7 +895,6 @@ static int rzg2l_mod_clock_endisable(struct clk_hw *hw, bool enable)
 	struct rzg2l_cpg_priv *priv = clock->priv;
 	unsigned int reg = clock->off;
 	struct device *dev = priv->dev;
-	unsigned long flags;
 	u32 bitmask = BIT(clock->bit);
 	u32 value;
 	int error;
@@ -907,14 +906,12 @@ static int rzg2l_mod_clock_endisable(struct clk_hw *hw, bool enable)
 
 	dev_dbg(dev, "CLK_ON %u/%pC %s\n", CLK_ON_R(reg), hw->clk,
 		enable ? "ON" : "OFF");
-	spin_lock_irqsave(&priv->rmw_lock, flags);
 
 	value = bitmask << 16;
 	if (enable)
 		value |= bitmask;
-	writel(value, priv->base + CLK_ON_R(reg));
 
-	spin_unlock_irqrestore(&priv->rmw_lock, flags);
+	writel(value, priv->base + CLK_ON_R(reg));
 
 	if (!enable)
 		return 0;
-- 
2.39.2