Re: [PATCH] HID: core: allow concurrent registration of drivers

[Benjamin Tissoires]

Hi,

On Mon, Jun 4, 2018 at 10:37 PM,  <Mario.Limonciello@xxxxxxxx> wrote:
> Benjamin,
>
> I had to make a minor change since I didn't see
>>  #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 <mario.limonciello@xxxxxxxx>

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,
>
>> -----Original Message-----
>> From: Benjamin Tissoires [mailto:benjamin.tissoires@xxxxxxxxxx]
>> Sent: Thursday, May 31, 2018 6:49 AM
>> To: Jiri Kosina; Limonciello, Mario
>> Cc: linux-input@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; 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@xxxxxxxxxxxxxxx # v4.17
>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>> ---
>>
>> 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
>