linux-kernel - [PATCH v1 2/5] regmap: mmio: Drop unneeded and duplicative checks around CLK calls

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Message-Id: <20220805205321.19452-2-andriy.shevchenko@linux.intel.com>
Date:   Fri,  5 Aug 2022 23:53:18 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mark Brown <broonie@...nel.org>,
        Aidan MacDonald <aidanmacdonald.0x0@...il.com>,
        linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: [PATCH v1 2/5] regmap: mmio: Drop unneeded and duplicative checks around CLK calls

The commit 6b8e090ecc3d ("regmap: use IS_ERR() to check clk_get()
results") assumes that CLK calls return the error pointer when clock
is not found. However in the current code the described situation
is simply impossible, because the regmap won't be created with
missed clock if requested. The only way when it can be the case is
what the above mentioned commit introduced by itself, when clock is
not provided.

Taking above into consideration, effectively revert the commit
6b8e090ecc3d and while at it, drop unneeded NULL checks since CLK
calls are NULL-aware.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/base/regmap/regmap-mmio.c | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c
index e83a2c3ba95a..e1923506a89a 100644
--- a/drivers/base/regmap/regmap-mmio.c
+++ b/drivers/base/regmap/regmap-mmio.c
@@ -146,16 +146,13 @@ static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val)
 	struct regmap_mmio_context *ctx = context;
 	int ret;
 
-	if (!IS_ERR(ctx->clk)) {
-		ret = clk_enable(ctx->clk);
-		if (ret < 0)
-			return ret;
-	}
+	ret = clk_enable(ctx->clk);
+	if (ret < 0)
+		return ret;
 
 	ctx->reg_write(ctx, reg, val);
 
-	if (!IS_ERR(ctx->clk))
-		clk_disable(ctx->clk);
+	clk_disable(ctx->clk);
 
 	return 0;
 }
@@ -227,16 +224,13 @@ static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val)
 	struct regmap_mmio_context *ctx = context;
 	int ret;
 
-	if (!IS_ERR(ctx->clk)) {
-		ret = clk_enable(ctx->clk);
-		if (ret < 0)
-			return ret;
-	}
+	ret = clk_enable(ctx->clk);
+	if (ret < 0)
+		return ret;
 
 	*val = ctx->reg_read(ctx, reg);
 
-	if (!IS_ERR(ctx->clk))
-		clk_disable(ctx->clk);
+	clk_disable(ctx->clk);
 
 	return 0;
 }
@@ -245,7 +239,7 @@ static void regmap_mmio_free_context(void *context)
 {
 	struct regmap_mmio_context *ctx = context;
 
-	if (!IS_ERR(ctx->clk) && !ctx->attached_clk) {
+	if (!ctx->attached_clk) {
 		clk_unprepare(ctx->clk);
 		clk_put(ctx->clk);
 	}
@@ -290,7 +284,6 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
 	ctx->regs = regs;
 	ctx->val_bytes = config->val_bits / 8;
 	ctx->relaxed_mmio = config->use_relaxed_mmio;
-	ctx->clk = ERR_PTR(-ENODEV);
 
 	switch (regmap_get_val_endian(dev, &regmap_mmio, config)) {
 	case REGMAP_ENDIAN_DEFAULT:
-- 
2.35.1