diff mbox series

[v9,1/9] HID: hid-sensor-hub: don't use stale platform-data on remove

Message ID 20241107114712.538976-2-heiko@sntech.de
State New
Headers show
Series Drivers to support the MCU on QNAP NAS devices | expand

Commit Message

Heiko Stuebner Nov. 7, 2024, 11:47 a.m. UTC
The hid-sensor-hub creates the individual device structs and transfers them
to the created mfd platform-devices via the platform_data in the mfd_cell.

Before e651a1da442a ("HID: hid-sensor-hub: Allow parallel synchronous reads")
the sensor-hub was managing access centrally, with one "completion" in the
hub's data structure, which needed to be finished on removal at the latest.

The mentioned commit then moved this central management to each hid sensor
device, resulting on a completion in each struct hid_sensor_hub_device.
The remove procedure was adapted to go through all sensor devices and
finish any pending "completion".

What this didn't take into account was, platform_device_add_data() that is
used by mfd_add{_hotplug}_devices() does a kmemdup on the submitted
platform-data. So the data the platform-device gets is a copy of the
original data, meaning that the device worked on a different completion
than what sensor_hub_remove() currently wants to access.

To fix that, use device_for_each_child() to go through each child-device
similar to how mfd_remove_devices() unregisters the devices later and
with that get the live platform_data to finalize the correct completion.

Fixes: e651a1da442a ("HID: hid-sensor-hub: Allow parallel synchronous reads")
Cc: stable@vger.kernel.org
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/hid/hid-sensor-hub.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

Comments

Lee Jones Nov. 12, 2024, 2:37 p.m. UTC | #1
On Thu, 07 Nov 2024, Jiri Kosina wrote:

> On Thu, 7 Nov 2024, Heiko Stübner wrote:
> 
> > This change was more or less a surprise find, because I wanted to make
> > the platform_data pointer in the mfd_cell struct const and this the hid
> > sensor hub stood out as doing something strange ;-) .
> > 
> > So patch 2 of this series actually depends on this change to not cause
> > build errors.
> 
> Ah, right.
> 
> > But seeing that we're after -rc6 alredy, I would assume the brunt of the 
> > mcu series might need to wait after 6.13-rc1 anyway - but I guess that 
> > depends on how Lee sees things ;-) .
> 
> OK, I am keeping my hands off it for the time being.

I can take it now with an Ack.
Lee Jones Dec. 11, 2024, 12:17 p.m. UTC | #2
On Tue, 12 Nov 2024, Lee Jones wrote:

> On Thu, 07 Nov 2024, Jiri Kosina wrote:
> 
> > On Thu, 7 Nov 2024, Heiko Stübner wrote:
> > 
> > > This change was more or less a surprise find, because I wanted to make
> > > the platform_data pointer in the mfd_cell struct const and this the hid
> > > sensor hub stood out as doing something strange ;-) .
> > > 
> > > So patch 2 of this series actually depends on this change to not cause
> > > build errors.
> > 
> > Ah, right.
> > 
> > > But seeing that we're after -rc6 alredy, I would assume the brunt of the 
> > > mcu series might need to wait after 6.13-rc1 anyway - but I guess that 
> > > depends on how Lee sees things ;-) .
> > 
> > OK, I am keeping my hands off it for the time being.
> 
> I can take it now with an Ack.

Looking to apply this set now.

Ack please.
Jiri Kosina Dec. 11, 2024, 12:24 p.m. UTC | #3
On Wed, 11 Dec 2024, Lee Jones wrote:

> > > > This change was more or less a surprise find, because I wanted to make
> > > > the platform_data pointer in the mfd_cell struct const and this the hid
> > > > sensor hub stood out as doing something strange ;-) .
> > > > 
> > > > So patch 2 of this series actually depends on this change to not cause
> > > > build errors.
> > > 
> > > Ah, right.
> > > 
> > > > But seeing that we're after -rc6 alredy, I would assume the brunt of the 
> > > > mcu series might need to wait after 6.13-rc1 anyway - but I guess that 
> > > > depends on how Lee sees things ;-) .
> > > 
> > > OK, I am keeping my hands off it for the time being.
> > 
> > I can take it now with an Ack.
> 
> Looking to apply this set now.
> 
> Ack please.

I'd preferer if Srinivas could ack this as the more specific maintainer. 
Srinivas, please? 

Thanks,
Srinivas Pandruvada Dec. 11, 2024, 2:23 p.m. UTC | #4
On Wed, 2024-12-11 at 13:24 +0100, Jiri Kosina wrote:
> On Wed, 11 Dec 2024, Lee Jones wrote:
> 
> > > > > This change was more or less a surprise find, because I
> > > > > wanted to make
> > > > > the platform_data pointer in the mfd_cell struct const and
> > > > > this the hid
> > > > > sensor hub stood out as doing something strange ;-) .
> > > > > 
> > > > > So patch 2 of this series actually depends on this change to
> > > > > not cause
> > > > > build errors.
> > > > 
> > > > Ah, right.
> > > > 
> > > > > But seeing that we're after -rc6 alredy, I would assume the
> > > > > brunt of the 
> > > > > mcu series might need to wait after 6.13-rc1 anyway - but I
> > > > > guess that 
> > > > > depends on how Lee sees things ;-) .
> > > > 
> > > > OK, I am keeping my hands off it for the time being.
> > > 
> > > I can take it now with an Ack.
> > 
> > Looking to apply this set now.
> > 
> > Ack please.
> 
> I'd preferer if Srinivas could ack this as the more specific
> maintainer. 
> Srinivas, please? 
My ACK is already in the patch:

Fixes: e651a1da442a ("HID: hid-sensor-hub: Allow parallel synchronous
reads")
Cc: stable@vger.kernel.org
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>


Thanks,
Srinivas

> 
> Thanks,
>
diff mbox series

Patch

diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 7bd86eef6ec7..4c94c03cb573 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -730,23 +730,30 @@  static int sensor_hub_probe(struct hid_device *hdev,
 	return ret;
 }
 
+static int sensor_hub_finalize_pending_fn(struct device *dev, void *data)
+{
+	struct hid_sensor_hub_device *hsdev = dev->platform_data;
+
+	if (hsdev->pending.status)
+		complete(&hsdev->pending.ready);
+
+	return 0;
+}
+
 static void sensor_hub_remove(struct hid_device *hdev)
 {
 	struct sensor_hub_data *data = hid_get_drvdata(hdev);
 	unsigned long flags;
-	int i;
 
 	hid_dbg(hdev, " hardware removed\n");
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
+
 	spin_lock_irqsave(&data->lock, flags);
-	for (i = 0; i < data->hid_sensor_client_cnt; ++i) {
-		struct hid_sensor_hub_device *hsdev =
-			data->hid_sensor_hub_client_devs[i].platform_data;
-		if (hsdev->pending.status)
-			complete(&hsdev->pending.ready);
-	}
+	device_for_each_child(&hdev->dev, NULL,
+			      sensor_hub_finalize_pending_fn);
 	spin_unlock_irqrestore(&data->lock, flags);
+
 	mfd_remove_devices(&hdev->dev);
 	mutex_destroy(&data->mutex);
 }