2023-09-21 21:32:21

by Dhruva Gole

[permalink] [raw]
Subject: [PATCH V2] firmware: ti_sci: Mark driver as non removable

The TI-SCI message protocol provides a way to communicate between
various compute processors with a central system controller entity. It
provides the fundamental device management capability and clock control
in the SOCs that it's used in.

The remove function failed to do all the necessary cleanup if
there are registered users. Some things are freed however which
likely results in an oops later on.

Ensure that the driver isn't unbound by suppressing its bind and unbind
sysfs attributes. As the driver is built-in there is no way to remove
device once bound.

We can also remove the ti_sci_remove call along with the
ti_sci_debugfs_destroy as there are no callers for it any longer.

Fixes: aa276781a64a ("firmware: Add basic support for TI System Control Interface (TI-SCI) protocol")
Reported-by: Uwe Kleine-König <[email protected]>
Closes: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Suggested-by: Uwe Kleine-König <[email protected]>
Acked-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Dhruva Gole <[email protected]>
---

Link to v1:
https://lore.kernel.org/linux-arm-kernel/[email protected]/

Changelog:
Rebased, updated the commit message and added Reported and Closes tag.

Cc: Tero Kristo <[email protected]>
Cc: Santosh Shilimkar <[email protected]>
Cc: Vibhore Vardhan <[email protected]>
Cc: Vignesh Raghavendra <[email protected]>

---

drivers/firmware/ti_sci.c | 46 +--------------------------------------
1 file changed, 1 insertion(+), 45 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index c288ae49f91c..ffca636cc13f 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -190,19 +190,6 @@ static int ti_sci_debugfs_create(struct platform_device *pdev,
return 0;
}

-/**
- * ti_sci_debugfs_destroy() - clean up log debug file
- * @pdev: platform device pointer
- * @info: Pointer to SCI entity information
- */
-static void ti_sci_debugfs_destroy(struct platform_device *pdev,
- struct ti_sci_info *info)
-{
- if (IS_ERR(info->debug_region))
- return;
-
- debugfs_remove(info->d);
-}
#else /* CONFIG_DEBUG_FS */
static inline int ti_sci_debugfs_create(struct platform_device *dev,
struct ti_sci_info *info)
@@ -3445,43 +3432,12 @@ static int ti_sci_probe(struct platform_device *pdev)
return ret;
}

-static int ti_sci_remove(struct platform_device *pdev)
-{
- struct ti_sci_info *info;
- struct device *dev = &pdev->dev;
- int ret = 0;
-
- of_platform_depopulate(dev);
-
- info = platform_get_drvdata(pdev);
-
- if (info->nb.notifier_call)
- unregister_restart_handler(&info->nb);
-
- mutex_lock(&ti_sci_list_mutex);
- if (info->users)
- ret = -EBUSY;
- else
- list_del(&info->node);
- mutex_unlock(&ti_sci_list_mutex);
-
- if (!ret) {
- ti_sci_debugfs_destroy(pdev, info);
-
- /* Safe to free channels since no more users */
- mbox_free_channel(info->chan_tx);
- mbox_free_channel(info->chan_rx);
- }
-
- return ret;
-}
-
static struct platform_driver ti_sci_driver = {
.probe = ti_sci_probe,
- .remove = ti_sci_remove,
.driver = {
.name = "ti-sci",
.of_match_table = of_match_ptr(ti_sci_of_match),
+ .suppress_bind_attrs = true,
},
};
module_platform_driver(ti_sci_driver);

base-commit: 940fcc189c51032dd0282cbee4497542c982ac59
--
2.34.1


2023-10-02 17:57:27

by Nishanth Menon

[permalink] [raw]
Subject: Re: [PATCH V2] firmware: ti_sci: Mark driver as non removable

Hi Dhruva Gole,

On Thu, 21 Sep 2023 14:40:26 +0530, Dhruva Gole wrote:
> The TI-SCI message protocol provides a way to communicate between
> various compute processors with a central system controller entity. It
> provides the fundamental device management capability and clock control
> in the SOCs that it's used in.
>
> The remove function failed to do all the necessary cleanup if
> there are registered users. Some things are freed however which
> likely results in an oops later on.
>
> [...]

I have applied the following to branch ti-drivers-soc-next on [1].
Thank you!

[1/1] firmware: ti_sci: Mark driver as non removable
commit: 7b7a224b1ba1703583b25a3641ad9798f34d832a

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D