linux-kernel - [PATCH v2 5/5] clk: Ingenic: Remove unnecessary spinlock when reading registers.

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Message-Id: <1576250472-124315-7-git-send-email-zhouyanjie@wanyeetech.com>
Date:   Fri, 13 Dec 2019 23:21:12 +0800
From:   周琰杰 (Zhou Yanjie) 
        <zhouyanjie@...yeetech.com>
To:     linux-mips@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        devicetree@...r.kernel.org, robh+dt@...nel.org,
        paul.burton@...s.com, paulburton@...nel.org, paul@...pouillou.net,
        mturquette@...libre.com, sboyd@...nel.org, mark.rutland@....com,
        sernia.zhou@...mail.com, zhenwenjin@...il.com
Subject: [PATCH v2 5/5] clk: Ingenic: Remove unnecessary spinlock when reading registers.

It is not necessary to use spinlock when reading registers,
so remove it from cgu.c.

Suggested-by: Paul Cercueil <paul@...pouillou.net>
Suggested-by: Paul Burton <paulburton@...nel.org>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@...yeetech.com>
---

Notes:
    v2:
    New Patch.

 drivers/clk/ingenic/cgu.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c
index ae1ddcb..3c95451 100644
--- a/drivers/clk/ingenic/cgu.c
+++ b/drivers/clk/ingenic/cgu.c
@@ -76,16 +76,13 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 	const struct ingenic_cgu_pll_info *pll_info;
 	unsigned m, n, od_enc, od;
 	bool bypass;
-	unsigned long flags;
 	u32 ctl;
 
 	clk_info = &cgu->clock_info[ingenic_clk->idx];
 	BUG_ON(clk_info->type != CGU_CLK_PLL);
 	pll_info = &clk_info->pll;
 
-	spin_lock_irqsave(&cgu->lock, flags);
 	ctl = readl(cgu->base + pll_info->pll_reg);
-	spin_unlock_irqrestore(&cgu->lock, flags);
 
 	m = (ctl >> pll_info->m_shift) & GENMASK(pll_info->m_bits - 1, 0);
 	m += pll_info->m_offset;
@@ -94,9 +91,7 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 	od_enc = ctl >> pll_info->od_shift;
 	od_enc &= GENMASK(pll_info->od_bits - 1, 0);
 
-	spin_lock_irqsave(&cgu->lock, flags);
 	ctl = readl(cgu->base + pll_info->bypass_reg);
-	spin_unlock_irqrestore(&cgu->lock, flags);
 
 	bypass = !pll_info->no_bypass_bit &&
 		 !!(ctl & BIT(pll_info->bypass_bit));
@@ -269,12 +264,9 @@ static int ingenic_pll_is_enabled(struct clk_hw *hw)
 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
-	unsigned long flags;
 	u32 ctl;
 
-	spin_lock_irqsave(&cgu->lock, flags);
 	ctl = readl(cgu->base + pll_info->pll_reg);
-	spin_unlock_irqrestore(&cgu->lock, flags);
 
 	return !!(ctl & BIT(pll_info->enable_bit));
 }
-- 
2.7.4