[PATCH v3 07/13] media: meson-ir-tx: Ensure clock is disabled on unbind

[PATCH v3 07/13] media: meson-ir-tx: Ensure clock is disabled on unbind

[Sean Young]

clk_prepare_enable() needs a call to clk_disable_unprepare() on
driver unbind. Make it devm managed.

Fixes: 49be1c78d575 ("media: rc: introduce Meson IR TX driver")
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/media/rc/meson-ir-tx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
index fded2c256f2a..e7bb107e6a84 100644
--- a/drivers/media/rc/meson-ir-tx.c
+++ b/drivers/media/rc/meson-ir-tx.c
@@ -288,8 +288,8 @@ static int meson_irtx_mod_clock_probe(struct meson_irtx *ir,
 	if (!np)
 		return -ENODEV;
 
-	clock = devm_clk_get(ir->dev, "xtal");
-	if (IS_ERR(clock) || clk_prepare_enable(clock))
+	clock = devm_clk_get_enabled(ir->dev, "xtal");
+	if (IS_ERR(clock))
 		return -ENODEV;
 
 	*clk_nr = IRB_MOD_XTAL3_CLK;
-- 
2.55.0


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Re: [PATCH v3 07/13] media: meson-ir-tx: Ensure clock is disabled on unbind

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

Pre-existing issues:
- [High] This problem wasn't introduced by this patch, but the error code from `devm_clk_get_enabled()` is unconditionally masked with `-ENODEV`, which breaks probe deferral.
- [High] This problem wasn't introduced by this patch, but the error return from `platform_get_irq()` is masked by returning `-ENODEV`, breaking probe deferral.
--

--- Patch [7]: [PATCH v3 07/13] media: meson-ir-tx: Ensure clock is disabled on unbind ---
commit 902362d56de8e550d8a16fef5053c172039aa2ab
Author: Sean Young <sean@mess.org>
Subject: media: meson-ir-tx: Ensure clock is disabled on unbind

This commit replaces the manual devm_clk_get and clk_prepare_enable calls
with devm_clk_get_enabled. This ensures that the clock is properly
disabled when the driver is unbound.

> diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
> index fded2c256f2a6..e7bb107e6a843 100644
> --- a/drivers/media/rc/meson-ir-tx.c
> +++ b/drivers/media/rc/meson-ir-tx.c
> @@ -288,8 +288,8 @@ static int meson_irtx_mod_clock_probe(struct meson_irtx *ir,
>  	if (!np)
>  		return -ENODEV;
>  
> -	clock = devm_clk_get(ir->dev, "xtal");
> -	if (IS_ERR(clock) || clk_prepare_enable(clock))
> +	clock = devm_clk_get_enabled(ir->dev, "xtal");
> +	if (IS_ERR(clock))
>  		return -ENODEV;

[Severity: High]
This is a pre-existing issue, but does dropping the actual error code from
devm_clk_get_enabled() and returning -ENODEV break probe deferral?

If the clock provider isn't ready, devm_clk_get_enabled() returns
-EPROBE_DEFER, which gets masked here. Should this return PTR_ERR(clock)
instead?

[ ... ]

While reviewing this file, I also noticed another pre-existing issue in
the same driver:

drivers/media/rc/meson-ir-tx.c:meson_irtx_probe() {
    ...
    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return -ENODEV;
    ...
}

[Severity: High]
This isn't a bug introduced by this patch, but would returning a hardcoded
-ENODEV here break probe deferral if the interrupt controller is not yet
ready?

When platform_get_irq() returns -EPROBE_DEFER, it seems the code currently
discards it. Would returning the actual error code be more appropriate?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1784715737.git.sean@mess.org?part=7

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[PATCH v3 08/13] media: meson-ir-tx: Ensure rc_free_device() is called on unbind

[Sean Young]

Make rc_dev devm managed.

Fixes: dccc0c3ddf8f ("media: rc: fix race between unregister and urb/irq callbacks")
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/media/rc/meson-ir-tx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
index e7bb107e6a84..abb107d19e8c 100644
--- a/drivers/media/rc/meson-ir-tx.c
+++ b/drivers/media/rc/meson-ir-tx.c
@@ -345,7 +345,7 @@ static int meson_irtx_probe(struct platform_device *pdev)
 	if (ret)
 		return dev_err_probe(dev, ret, "irq request failed\n");
 
-	rc = rc_allocate_device(RC_DRIVER_IR_RAW_TX);
+	rc = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW_TX);
 	if (!rc)
 		return -ENOMEM;
 
@@ -358,10 +358,8 @@ static int meson_irtx_probe(struct platform_device *pdev)
 	rc->s_tx_duty_cycle = meson_irtx_set_duty_cycle;
 
 	ret = devm_rc_register_device(dev, rc);
-	if (ret < 0) {
-		rc_free_device(rc);
+	if (ret < 0)
 		return dev_err_probe(dev, ret, "rc_dev registration failed\n");
-	}
 
 	return 0;
 }
-- 
2.55.0


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[PATCH v3 09/13] media: meson-ir-tx: Ensure probe error is propagated

[Sean Young]

devm_clk_get_enabled() may return -EPROBE_DEFER which needs to be
propagated else the probe will not be deferred, it will fail instead.

Fixes: 49be1c78d575 ("media: rc: introduce Meson IR TX driver")
Signed-off-by: Sean Young <sean@mess.org>
---
 drivers/media/rc/meson-ir-tx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
index abb107d19e8c..174d5135e1bb 100644
--- a/drivers/media/rc/meson-ir-tx.c
+++ b/drivers/media/rc/meson-ir-tx.c
@@ -290,7 +290,7 @@ static int meson_irtx_mod_clock_probe(struct meson_irtx *ir,
 
 	clock = devm_clk_get_enabled(ir->dev, "xtal");
 	if (IS_ERR(clock))
-		return -ENODEV;
+		return PTR_ERR(clock);
 
 	*clk_nr = IRB_MOD_XTAL3_CLK;
 	ir->clk_rate = clk_get_rate(clock) / 3;
@@ -324,7 +324,7 @@ static int meson_irtx_probe(struct platform_device *pdev)
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
-		return -ENODEV;
+		return irq;
 
 	ir->dev = dev;
 	ir->carrier = MIRTX_DEFAULT_CARRIER;
-- 
2.55.0


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