linux-kernel - [PATCH 1/6] clk: meson: mpll: Delete a meaningless spinlock from the MPLL

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Message-Id: <20240920-mpll_spinlock-v1-1-5249a9a7e2b7@amlogic.com>
Date: Fri, 20 Sep 2024 16:16:11 +0800
From: Chuan Liu via B4 Relay <devnull+chuan.liu.amlogic.com@...nel.org>
To: Neil Armstrong <neil.armstrong@...aro.org>, 
 Jerome Brunet <jbrunet@...libre.com>, 
 Michael Turquette <mturquette@...libre.com>, 
 Stephen Boyd <sboyd@...nel.org>, Kevin Hilman <khilman@...libre.com>, 
 Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Cc: linux-amlogic@...ts.infradead.org, linux-clk@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Chuan Liu <chuan.liu@...ogic.com>
Subject: [PATCH 1/6] clk: meson: mpll: Delete a meaningless spinlock from
 the MPLL

From: Chuan Liu <chuan.liu@...ogic.com>

The existing locking mechanism of CCF can effectively avoid concurrent
register access. struct meson_clk_mpll_data has no meaning in defining
a spinlock repeatedly.

Signed-off-by: Chuan Liu <chuan.liu@...ogic.com>
---
 drivers/clk/meson/clk-mpll.c | 11 -----------
 drivers/clk/meson/clk-mpll.h |  1 -
 2 files changed, 12 deletions(-)

diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
index f639d56f0fd3..aa9abd06ae65 100644
--- a/drivers/clk/meson/clk-mpll.c
+++ b/drivers/clk/meson/clk-mpll.c
@@ -112,26 +112,15 @@ static int mpll_set_rate(struct clk_hw *hw,
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
 	unsigned int sdm, n2;
-	unsigned long flags = 0;
 
 	params_from_rate(rate, parent_rate, &sdm, &n2, mpll->flags);
 
-	if (mpll->lock)
-		spin_lock_irqsave(mpll->lock, flags);
-	else
-		__acquire(mpll->lock);
-
 	/* Set the fractional part */
 	meson_parm_write(clk->map, &mpll->sdm, sdm);
 
 	/* Set the integer divider part */
 	meson_parm_write(clk->map, &mpll->n2, n2);
 
-	if (mpll->lock)
-		spin_unlock_irqrestore(mpll->lock, flags);
-	else
-		__release(mpll->lock);
-
 	return 0;
 }
 
diff --git a/drivers/clk/meson/clk-mpll.h b/drivers/clk/meson/clk-mpll.h
index a991d568c43a..4ffd3aeef799 100644
--- a/drivers/clk/meson/clk-mpll.h
+++ b/drivers/clk/meson/clk-mpll.h
@@ -20,7 +20,6 @@ struct meson_clk_mpll_data {
 	struct parm misc;
 	const struct reg_sequence *init_regs;
 	unsigned int init_count;
-	spinlock_t *lock;
 	u8 flags;
 };
 

-- 
2.42.0