FAILED: patch "[PATCH] pwm: imx-tpm: Count the number of enabled channels in probe" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] pwm: imx-tpm: Count the number of enabled channels in probe" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 3962c24f2d14e8a7f8a23f56b7ce320523947342
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050332-washer-legislate-ef0e@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3962c24f2d14e8a7f8a23f56b7ce320523947342 Mon Sep 17 00:00:00 2001
From: "Viorel Suman (OSS)" <viorel.suman@oss.nxp.com>
Date: Wed, 11 Mar 2026 14:33:09 +0200
Subject: [PATCH] pwm: imx-tpm: Count the number of enabled channels in probe
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

On a soft reset TPM PWM IP may preserve its internal state from previous
runtime, therefore on a subsequent OS boot and driver probe
"enable_count" value and TPM PWM IP internal channels "enabled" states
may get unaligned. In consequence on a suspend/resume cycle the call "if
(--tpm->enable_count == 0)" may lead to "enable_count" overflow the
system being blocked from entering suspend due to:

   if (tpm->enable_count > 0)
       return -EBUSY;

Fix the problem by counting the enabled channels in probe function.

Signed-off-by: Viorel Suman (OSS) <viorel.suman@oss.nxp.com>
Fixes: 738a1cfec2ed ("pwm: Add i.MX TPM PWM driver support")
Link: https://patch.msgid.link/20260311123309.348904-1-viorel.suman@oss.nxp.com
Cc: stable@vger.kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index 5b399de16d60..80fdb3303400 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -352,7 +352,7 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev)
 	struct clk *clk;
 	void __iomem *base;
 	int ret;
-	unsigned int npwm;
+	unsigned int i, npwm;
 	u32 val;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
@@ -382,6 +382,13 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev)
 
 	mutex_init(&tpm->lock);
 
+	/* count the enabled channels */
+	for (i = 0; i < npwm; ++i) {
+		val = readl(base + PWM_IMX_TPM_CnSC(i));
+		if (FIELD_GET(PWM_IMX_TPM_CnSC_ELS, val))
+			++tpm->enable_count;
+	}
+
 	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");

[PATCH 6.1.y] pwm: imx-tpm: Count the number of enabled channels in probe

[Sasha Levin]

From: "Viorel Suman (OSS)" <viorel.suman@oss.nxp.com>

[ Upstream commit 3962c24f2d14e8a7f8a23f56b7ce320523947342 ]

On a soft reset TPM PWM IP may preserve its internal state from previous
runtime, therefore on a subsequent OS boot and driver probe
"enable_count" value and TPM PWM IP internal channels "enabled" states
may get unaligned. In consequence on a suspend/resume cycle the call "if
(--tpm->enable_count == 0)" may lead to "enable_count" overflow the
system being blocked from entering suspend due to:

   if (tpm->enable_count > 0)
       return -EBUSY;

Fix the problem by counting the enabled channels in probe function.

Signed-off-by: Viorel Suman (OSS) <viorel.suman@oss.nxp.com>
Fixes: 738a1cfec2ed ("pwm: Add i.MX TPM PWM driver support")
Link: https://patch.msgid.link/20260311123309.348904-1-viorel.suman@oss.nxp.com
Cc: stable@vger.kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
[ substituted `base` with `tpm->base` and `npwm` with `tpm->chip.npwm` to match the older non-devm probe layout ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pwm/pwm-imx-tpm.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index 081f511cd2130..e1caaef7dbd16 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -350,6 +350,7 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev)
 {
 	struct imx_tpm_pwm_chip *tpm;
 	int ret;
+	unsigned int i;
 	u32 val;
 
 	tpm = devm_kzalloc(&pdev->dev, sizeof(*tpm), GFP_KERNEL);
@@ -383,6 +384,13 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev)
 
 	mutex_init(&tpm->lock);
 
+	/* count the enabled channels */
+	for (i = 0; i < tpm->chip.npwm; ++i) {
+		val = readl(tpm->base + PWM_IMX_TPM_CnSC(i));
+		if (FIELD_GET(PWM_IMX_TPM_CnSC_ELS, val))
+			++tpm->enable_count;
+	}
+
 	ret = pwmchip_add(&tpm->chip);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
-- 
2.53.0

Re: FAILED: patch "[PATCH] pwm: imx-tpm: Count the number of enabled channels in probe" failed to apply to 6.1-stable tree

[Uwe Kleine-König]

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Hello Greg,

On Sun, May 03, 2026 at 01:46:32PM +0200, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 6.1-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
> git checkout FETCH_HEAD
> git cherry-pick -x 3962c24f2d14e8a7f8a23f56b7ce320523947342
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050332-washer-legislate-ef0e@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
> 

You wrote already on 2026-05-03 about this patch that failed to apply to
6.6, 6.1, 5.15 and 5.10. I replied to the 6.6 one with the exact patch
that Sasha now recreated in reply to this new 6.1 failure. I would have
expected that the 6.6 backport is tried to be applied to 6.1 and the
other older versions given the mainline original doesn't apply cleanly.

:-( that this resulted in duplicate work being done

Uwe

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