Re: [4.15 stable regression] "Bluetooth: btusb: Fix quirk for Atheros 1525/QCA6174" breaks bluetooth on some devices

[Takashi Iwai <tiwai@suse.de>]

On Fri, 27 Apr 2018 11:23:49 +0200,
Hans de Goede wrote:
> 
> Hi,
> 
> On 27-04-18 10:57, Hans de Goede wrote:
> >> -- 8< --
> >> From: Takashi Iwai <tiwai@suse.de>
> >> Subject: [PATCH] Bluetooth: btusb: Apply QCQ_ROME setup for BTUSB_ATH3012
> >>   quirk, too
> >>
> >> In commit f44cb4b19ed4 ("Bluetooth: btusb: Fix quirk for Atheros
> >> 1525/QCA6174") we tried to address the non-working Atheros BT devices
> >> by changing the quirk from BTUSB_ATH3012 to BTUSB_QCQ_ROME.  This made
> >> such devices working while it turned out to break other existing chips
> >> with the very same USB ID.
> >>
> >> This is another attempt to tackle the issue.  The essential point to
> >> use BTUSB_QCA_ROME is to apply the btusb_setup_qca() and do RAM-
> >> patching.  And the previous attempt failed because btusb_setup_qcq()
> >> returns -ENODEV if the ROM version doesn't match with the expected
> >> ones.  For some devices that have already the "correct" ROM versions,
> >> we may just skip the setup procedure and continue the rest.
> >>
> >> So, this patch applies btusb_setup_qca() also in BTUSB_ATH3012 quirk,
> >> and adds a check of the ROM version in the function to skip the setup
> >> if the ROM version looks already sane.
> >>
> >> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> >> ---
> >>   drivers/bluetooth/btusb.c | 5 +++++
> >>   1 file changed, 5 insertions(+)
> >>
> >> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> >> index c8c8b0b8d333..720356320ace 100644
> >> --- a/drivers/bluetooth/btusb.c
> >> +++ b/drivers/bluetooth/btusb.c
> >> @@ -2673,6 +2673,10 @@ static int btusb_setup_qca(struct hci_dev *hdev)
> >>           return err;
> >>       ver_rom = le32_to_cpu(ver.rom_version);
> >> +    /* Don't care about high ROM versions */
> >> +    if (ver_rom & ~0xffffU)
> >> +        return 0;
> >> +
> >>       for (i = 0; i < ARRAY_SIZE(qca_devices_table); i++) {
> >>           if (ver_rom == qca_devices_table[i].rom_version)
> >>               info = &qca_devices_table[i];
> >> @@ -3055,6 +3059,7 @@ static int btusb_probe(struct usb_interface *intf,
> >>       }
> >>       if (id->driver_info & BTUSB_ATH3012) {
> >> +        data->setup_on_usb = btusb_setup_qca;
> >>           hdev->set_bdaddr = btusb_set_bdaddr_ath3012;
> >>           set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
> >>           set_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks);
> >>
> 
> 
> p.s.
> 
> This change makes the BTUSB_ATH3012 / BTUSB_QCA_ROME code-paths almost
> the same, the only difference is the BTUSB_ATH3012 path also setting the
> HCI_QUIRK_STRICT_DUPLICATE_FILTER flag. Does anyone know if it perhaps
> would be correct to also set that flag for the QCA_ROME chipset and
> then unify the 2 code-paths?

I belive it's the way to go, but obviously needs testing :)


Takashi