Hi,

On Mon, Jun 4, 2018 at 10:37 PM,  [off-list ref] wrote:

Benjamin,

I had to make a minor change since I didn't see

quoted

 #define HID_STAT_DUP_DETECTED        BIT(2)

In Linus's tree.

I tested with master today though and it seems to be working now with your patch across
several boot attempts.

Tested-by: Mario Limonciello <redacted>

Thanks a lot Mario.

Jiri, I do not see this patch in your tree. Could you take it soon-ish
so we can backport it in 4.17 ASAP?

Cheers,
Benjamin

Thanks,

quoted

-----Original Message-----
From: Benjamin Tissoires [mailto:benjamin.tissoires@redhat.com]
Sent: Thursday, May 31, 2018 6:49 AM
To: Jiri Kosina; Limonciello, Mario
Cc: linux-input@vger.kernel.org; linux-kernel@vger.kernel.org; Benjamin Tissoires
Subject: [PATCH] HID: core: allow concurrent registration of drivers

Detected on the Dell XPS 9365.
The laptop has 2 devices that benefit from the hid-generic auto-unbinding.
When those 2 devices are presented to the userspace, udev loads both
wacom and hid-multitouch. When this happens, the code in
__hid_bus_reprobe_drivers() is called concurrently and the second device
gets reprobed twice.
An other bug in the power_supply subsystem prevent to remove the wacom
driver if it just finished its initialization, which basically kills
the wacom node.

Fixes c17a7476e4c4 ("HID: core: rewrite the hid-generic automatic unbind")

Cc: stable@vger.kernel.org # v4.17
Signed-off-by: Benjamin Tissoires <redacted>
---

Hi Mario,

can you please test this on your faulty XPS?
I think it'll fix the issue, but I can not reproduce, so better wait for
your confirmation.

Jiri, ideally I would love to see this in v4.17 final, but Mario seems
to be on PTO until next week. I guess we'll just push this in v4.17.1
then. Also, if you can double check that it makes sense, that would be
nice :)

Cheers,
Benjamin

 drivers/hid/hid-core.c | 5 ++++-
 include/linux/hid.h    | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 2f7367b1de00..7afed0c0f9e5 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c

@@ -1960,6 +1960,8 @@ static int hid_device_probe(struct device *dev)
      }
      hdev->io_started = false;

+     clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
+
      if (!hdev->driver) {
              id = hid_match_device(hdev, hdrv);
              if (id == NULL) {

@@ -2223,7 +2225,8 @@ static int __hid_bus_reprobe_drivers(struct device *dev,

void *data)
      struct hid_device *hdev = to_hid_device(dev);

      if (hdev->driver == hdrv &&
-         !hdrv->match(hdev, hid_ignore_special_drivers))
+         !hdrv->match(hdev, hid_ignore_special_drivers) &&
+         !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
              return device_reprobe(dev);

      return 0;

diff --git a/include/linux/hid.h b/include/linux/hid.h
index ee2510019033..aee281522c6d 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h

@@ -517,6 +517,7 @@ struct hid_output_fifo {
 #define HID_STAT_ADDED               BIT(0)
 #define HID_STAT_PARSED              BIT(1)
 #define HID_STAT_DUP_DETECTED        BIT(2)
+#define HID_STAT_REPROBED    BIT(3)

 struct hid_input {
      struct list_head list;

@@ -585,7 +586,7 @@ struct hid_device {
              /* device report descriptor */
      bool battery_avoid_query;
 #endif

-     unsigned int status;                                            /* see

STAT flags above */
+     unsigned long status;                                           /* see
STAT flags above */
      unsigned claimed;                                               /*
Claimed by hidinput, hiddev? */
      unsigned quirks;                                                /* Various
quirks the device can pull on us */
      bool io_started;                                                /* If IO has started
*/
--
2.14.3