linux-kernel - camss: Missing cleanup on probe error

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Message-ID: <5898403.lOV4Wx5bFT@g550jk>
Date:   Tue, 24 Jan 2023 21:02:30 +0100
From:   Luca Weiss <luca@...tu.xyz>
To:     Todor Tomov <todor.too@...il.com>,
        Robert Foss <robert.foss@...aro.org>
Cc:     linux-media@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org, ~postmarketos/upstreaming@...ts.sr.ht
Subject: camss: Missing cleanup on probe error

Hi all,

I hit an issue that was already fixed with upstream commit 3d658980e6da 
("media: camss: Do not attach an already attached power domain on MSM8916 
platform") but this showed that some error handling is missing in camss_probe.

After these errors the resources aren't cleaned up and e.g. sensor drivers 
still try to probe but fail quite badly because some things are NULL or 
whatever.

[    1.979098] qcom-camss fda0ac00.camss: Failed to configure power domains: 
-17
[    1.989327] qcom-camss: probe of fda0ac00.camss failed with error -17

The commit causing this (or at least part of this) is 2f6f8af67203 ("media: 
camss: Refactor VFE power domain toggling")

I tried a bit to add some error handling but in this case it now fails at 
v4l2_device_unregister_subdev -> media_device_unregister_entity -> 
__media_device_unregister_entity -> ida_free.
And I'm not really sure how to fix (and honestly not super motivated).

See following patch (formatting probably messed up, sorry). Maybe someone who 
knows a bit more about the driver or the media subsystem can fix this, thanks!

Regards
Luca

diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/
platform/qcom/camss/camss.c
index 16545cecc4f4..0ba3c378d241 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -1836,21 +1836,26 @@ static int camss_probe(struct platform_device *pdev)
 		}
 	}

-	ret = camss_configure_pd(camss);
+	//ret = camss_configure_pd(camss);
+	ret = -17;
 	if (ret < 0) {
 		dev_err(dev, "Failed to configure power domains: %d\n", 
ret);
-		return ret;
+		goto err_configure_pd;
 	}

 	pm_runtime_enable(dev);

 	return 0;

+err_configure_pd:
+	media_device_unregister(&camss->media_dev);
+	media_device_cleanup(&camss->media_dev);
 err_register_subdevs:
 	camss_unregister_entities(camss);
 err_register_entities:
 	v4l2_device_unregister(&camss->v4l2_dev);
 err_cleanup:
+	v4l2_async_nf_unregister(&camss->notifier);
 	v4l2_async_nf_cleanup(&camss->notifier);

 	return ret;