Hi Hans,
>>>>> Commit 61f5acea8737 ("Bluetooth: btusb: Restore QCA Rome suspend/resume fix
>>>>> with a "rewritten" version") applied the USB_QUIRK_RESET_RESUME to all QCA
>>>>> btusb devices. But it turns out that the resume problems are not caused by
>>>>> the QCA Rome chipset, on most platforms it resumes fine. The resume
>>>>> problems are actually a platform problem (likely the platform cutting all
>>>>> power when suspended).
>>>>>
>>>>> The USB_QUIRK_RESET_RESUME quirk also disable runtime suspend, so by
>>>>> matching on usb-ids, we're causing all boards with these chips to use extra
>>>>> power, to fix resume problems which only happen on some boards.
>>>>>
>>>>> This commit fixes this by applying the quirk based on DMI matching instead
>>>>> of on usb-ids, so that we match the platform and not the chipset.
>>>> just for the record, can we include the /sys/kernel/debug/usb/devices for that device here.
>>>
>>> Will do.
>>>
>>>>> Fixes: 61f5acea8737 ("Bluetooth: btusb: Restore QCA Rome suspend/resume..")
>>>>> Cc: stable@xxxxxxxxxxxxxxx
>>>>> Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
>>>>> Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
>>>>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>>>>> ---
>>>>> drivers/bluetooth/btusb.c | 26 ++++++++++++++++++++------
>>>>> 1 file changed, 20 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
>>>>> index 2a55380ad730..a6023667f3b4 100644
>>>>> --- a/drivers/bluetooth/btusb.c
>>>>> +++ b/drivers/bluetooth/btusb.c
>>>>> @@ -21,6 +21,7 @@
>>>>> *
>>>>> */
>>>>>
>>>>> +#include <linux/dmi.h>
>>>>> #include <linux/module.h>
>>>>> #include <linux/usb.h>
>>>>> #include <linux/usb/quirks.h>
>>>>> @@ -379,6 +380,22 @@ static const struct usb_device_id blacklist_table[] = {
>>>>> { } /* Terminating entry */
>>>>> };
>>>>>
>>>>> +/*
>>>>> + * The btusb build into some devices needs to be reset on resume, this is a
>>>> Actually “btusb” is a driver name. So “Bluetooth USB modules”
>>>>> + * problem with the platform (likely shutting off all power) not with the
>>>>> + * btusb chip itself. So we use a DMI list to match known broken platforms.
>>>> Here s/btusb/module/
>>>>> + */
>>>>> +static const struct dmi_system_id btusb_plat_needs_reset_resume_list[] = {
>>>> I prefer to use _table instead of _list. Also drop the _plat_ part since that seems obvious.
>>>>> + {
>>>>> + /* Lenovo yoga 920 */
>>>> Use “Yoga" please.
>>>
>>> I will fix all of the above.
>>>
>>>> And I would include “(QCA Rome device VID:PID)” so that we have a record of some sorts.
>>>>> + .matches = {
>>>>> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>>>>> + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo YOGA 920”),
>>>> No DMI_EXACT_MATCH?
>>>
>>> The DMI data actually has:
>>>
>>> "Lenovo YOGA 920-13IKB"
>>>
>>> I'm not using DMI_EXACT_MATCH on purpose here, I think Lenovo
>>> might change the "-13IKB" part and I don't expect them to fix
>>> this bug on newer revisions.
>> that is fine. What about the “LENOVO” vendor match? Should that be an exact match?
>
> It could be an exact match, in general I tend to not use DMI_EXACT_MATCH
> unless necessary though, as vendors sometimes add whitespace padding after
> the contents. Esp. Asus is known to do this. But if you want me to change it
> over to DMI_EXACT_MATCH I can do that for the non RFC version which I plan
> to send tomorrow (I just got test feedback that this version works for the
> reporter).
I just mentioned it since in the hci_bcm.c we used DMI_EXACT_MATCH for the Lenovo hardware.
Regards
Marcel