Return-Path: Subject: Re: [PATCH] Bluetooth: btusb: Only check needs_reset_resume DMI table for QCA rome chipsets To: Jeremy Cline , Marcel Holtmann , Gustavo Padovan , Johan Hedberg Cc: linux-bluetooth@vger.kernel.org, stable@vger.kernel.org, Jeremy Cline References: <20180427092643.27140-1-hdegoede@redhat.com> <0100016307676ed2-fd5830a5-1933-4fc2-b356-a5112a65579f-000000@email.amazonses.com> From: Hans de Goede Message-ID: <55a828e6-01b3-891b-acaa-1bb12aa73a8c@redhat.com> Date: Fri, 27 Apr 2018 20:43:16 +0200 MIME-Version: 1.0 In-Reply-To: <0100016307676ed2-fd5830a5-1933-4fc2-b356-a5112a65579f-000000@email.amazonses.com> Content-Type: text/plain; charset=utf-8; format=flowed List-ID: Hi, On 04/27/2018 04:00 PM, Jeremy Cline wrote: > On 04/27/2018 05:26 AM, Hans de Goede wrote: >> Jeremy Cline correctly points out in rhbz#1514836 that a device where the >> QCA rome chipset needs the USB_QUIRK_RESET_RESUME quirk, may also ship >> with a different wifi/bt chipset in some configurations. >> >> If that is the case then we are needlessly penalizing those other chipsets >> with a reset-resume quirk, typically causing 0.4W extra power use because >> this disables runtime-pm. >> >> This commit moves the DMI table check to a btusb_check_needs_reset_resume() >> helper (so that we can easily also call it for other chipsets) and calls >> this new helper only for QCA_ROME chipsets for now. >> >> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1514836 >> Cc: stable@vger.kernel.org >> Cc: Jeremy Cline >> Suggested-by: Jeremy Cline >> Signed-off-by: Hans de Goede >> --- >> drivers/bluetooth/btusb.c | 10 +++++++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c >> index f064984c9ec0..15e7cdca6eb5 100644 >> --- a/drivers/bluetooth/btusb.c >> +++ b/drivers/bluetooth/btusb.c >> @@ -2863,6 +2863,12 @@ static int btusb_config_oob_wake(struct hci_dev *hdev) >> } >> #endif >> >> +static void btusb_check_needs_reset_resume(struct usb_interface *intf) >> +{ >> + if (dmi_check_system(btusb_needs_reset_resume_table)) >> + interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME; >> +} >> + >> static int btusb_probe(struct usb_interface *intf, >> const struct usb_device_id *id) >> { >> @@ -2985,9 +2991,6 @@ static int btusb_probe(struct usb_interface *intf, >> hdev->send = btusb_send_frame; >> hdev->notify = btusb_notify; >> >> - if (dmi_check_system(btusb_needs_reset_resume_table)) >> - interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME; >> - >> #ifdef CONFIG_PM >> err = btusb_config_oob_wake(hdev); >> if (err) >> @@ -3076,6 +3079,7 @@ static int btusb_probe(struct usb_interface *intf, >> data->setup_on_usb = btusb_setup_qca; >> hdev->set_bdaddr = btusb_set_bdaddr_ath3012; >> set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks); >> + btusb_check_needs_reset_resume(intf); > > If we later need the quirk applied to an Intel chipset for a particular > DMI, this call would get added to the Intel block and then the quirk > would start getting applied to the Intel variety of the XPS 13 9360 > again, right? > > I have a feeling that's a rather large "if" and I don't have any idea > how likely it is. Is it even something worth worrying about? ATM that seems rather unlikely, but we are tracking the USB-ids to which the DMI quirks belong (as comments) so we can later switch from a dmi-id only check to a combined dmi + usb-id check if necessary. Regards, Hans