linux-kernel - [PATCH AUTOSEL 5.4 22/28] pwm: tegra: Don't modify HW state in .remove callback

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: <20210710235107.3221840-22-sashal@kernel.org>
Date:   Sat, 10 Jul 2021 19:51:01 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Thierry Reding <thierry.reding@...il.com>,
        Sasha Levin <sashal@...nel.org>, linux-pwm@...r.kernel.org,
        linux-tegra@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 22/28] pwm: tegra: Don't modify HW state in .remove callback

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>

[ Upstream commit 86f7fa71cd830d18d7ebcaf719dffd5ddfe1acdd ]

A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pwm/pwm-tegra.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index aa12fb3ed92e..3d55e30a6866 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -232,7 +232,6 @@ static int tegra_pwm_probe(struct platform_device *pdev)
 static int tegra_pwm_remove(struct platform_device *pdev)
 {
 	struct tegra_pwm_chip *pc = platform_get_drvdata(pdev);
-	unsigned int i;
 	int err;
 
 	if (WARN_ON(!pc))
@@ -242,18 +241,6 @@ static int tegra_pwm_remove(struct platform_device *pdev)
 	if (err < 0)
 		return err;
 
-	for (i = 0; i < pc->chip.npwm; i++) {
-		struct pwm_device *pwm = &pc->chip.pwms[i];
-
-		if (!pwm_is_enabled(pwm))
-			if (clk_prepare_enable(pc->clk) < 0)
-				continue;
-
-		pwm_writel(pc, i, 0);
-
-		clk_disable_unprepare(pc->clk);
-	}
-
 	reset_control_assert(pc->rst);
 	clk_disable_unprepare(pc->clk);
 
-- 
2.30.2