linux-kernel - [PATCH v3 21/22] i2c: tegra: Initialization div-clk rate unconditionally

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200903005300.7894-22-digetx@gmail.com>
Date:   Thu,  3 Sep 2020 03:52:59 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Laxman Dewangan <ldewangan@...dia.com>,
        Wolfram Sang <wsa@...-dreams.de>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     linux-i2c@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 21/22] i2c: tegra: Initialization div-clk rate unconditionally

It doesn't make sense to conditionalize the div-clk rate changes because
rate is fixed and it won't ever change once it's set at the driver's probe
time. All further changes are NO-OPs because CCF caches rate and skips
rate-change if rate is unchanged.

Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/i2c/busses/i2c-tegra.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 79caf87bb4c0..bc7954c8a5a0 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -601,7 +601,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
 	return -ETIMEDOUT;
 }
 
-static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
+static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 {
 	u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh;
 	int err;
@@ -656,16 +656,14 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
 	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
 		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
 
-	if (!clk_reinit) {
-		clk_multiplier = (tlow + thigh + 2);
-		clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
-		err = clk_set_rate(i2c_dev->div_clk,
-				   i2c_dev->bus_clk_rate * clk_multiplier);
-		if (err) {
-			dev_err(i2c_dev->dev,
-				"failed to set div-clk rate: %d\n", err);
-			return err;
-		}
+	clk_multiplier  = tlow + thigh + 2;
+	clk_multiplier *= i2c_dev->clk_divisor_non_hs_mode + 1;
+
+	err = clk_set_rate(i2c_dev->div_clk,
+			   i2c_dev->bus_clk_rate * clk_multiplier);
+	if (err) {
+		dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
+		return err;
 	}
 
 	if (!i2c_dev->is_dvc && !i2c_dev->is_vi) {
@@ -1163,7 +1161,7 @@ static int tegra_i2c_error_recover(struct tegra_i2c_dev *i2c_dev,
 	if (i2c_dev->msg_err == I2C_ERR_NONE)
 		return 0;
 
-	tegra_i2c_init(i2c_dev, true);
+	tegra_i2c_init(i2c_dev);
 
 	/* start recovery upon arbitration loss in single master mode */
 	if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
@@ -1303,7 +1301,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 		if (!time_left && !completion_done(&i2c_dev->dma_complete)) {
 			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
-			tegra_i2c_init(i2c_dev, true);
+			tegra_i2c_init(i2c_dev);
 			return -ETIMEDOUT;
 		}
 
@@ -1324,7 +1322,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 	if (time_left == 0) {
 		dev_err(i2c_dev->dev, "I2C transfer timed out\n");
-		tegra_i2c_init(i2c_dev, true);
+		tegra_i2c_init(i2c_dev);
 		return -ETIMEDOUT;
 	}
 
@@ -1752,7 +1750,7 @@ static int tegra_i2c_init_runtime_pm_and_hardware(struct tegra_i2c_dev *i2c_dev)
 	}
 
 	/* initialize hardware state */
-	ret = tegra_i2c_init(i2c_dev, false);
+	ret = tegra_i2c_init(i2c_dev);
 
 	pm_runtime_put(i2c_dev->dev);
 
@@ -1907,7 +1905,7 @@ static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
 	 * domain ON.
 	 */
 	if (i2c_dev->is_vi) {
-		ret = tegra_i2c_init(i2c_dev, true);
+		ret = tegra_i2c_init(i2c_dev);
 		if (ret)
 			goto disable_div_clk;
 	}
@@ -1961,7 +1959,7 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev)
 	if (err)
 		return err;
 
-	err = tegra_i2c_init(i2c_dev, false);
+	err = tegra_i2c_init(i2c_dev);
 	if (err)
 		return err;
 
-- 
2.27.0