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Message-ID: <172a1b38-bc36-059b-4d90-f3afee1b8483@molgen.mpg.de>
Date: Tue, 18 Jan 2022 13:16:13 +0100
From: Paul Menzel <pmenzel@...gen.mpg.de>
To: Ismael Ferreras Morezuelas <swyterzone@...il.com>
Cc: Johan Hedberg <johan.hedberg@...il.com>,
Luiz Augusto von Dentz <luiz.dentz@...il.com>,
linux-bluetooth@...r.kernel.org, linux-kernel@...r.kernel.org,
Hans de Goede <hdegoede@...hat.com>,
Marcel Holtmann <marcel@...tmann.org>
Subject: Re: [PATCH v2] Bluetooth: btusb: Add a new quirk to skip
HCI_FLT_CLEAR_ALL on fake CSR controllers
Dear Ismael,
Thank you for working on fixing these controllers. Just a nit, to make
the commit message summary a little shorter, you can just write:
Add quirk to skip HCI_FLT_CLEAR_ALL on fake CSR controllers
Am 18.01.22 um 08:14 schrieb Ismael Ferreras Morezuelas:
> Another subset of the more recent batch of Chinese clones aren't
> specs-compliant and seem to lock up whenever they receive a
> HCI_OP_SET_EVENT_FLT with flt_type set to zero/HCI_FLT_CLEAR_ALL,
> which on Linux happens right at BR/EDR setup.
>
> So, while all the previous efforts to wrangle the herd of fake CSRs
> seem to be paying off (and these also get detected as such) we
> still need to take care of this quirk; testers seem to agree
> that these dongles tend to work well enough afterwards.
>
> From some cursory USB packet capture on Windows it seems like
> that driver doesn't appear to use this clear-all functionality at all.
>
> This patch was tested on some really popular AliExpress-style
> dongles, in my case marked as "V5.0". Chip markings: UG8413,
> the backside of the PCB says "USB Dangel" (sic).
>
> Here is the `hciconfig -a` output; for completeness:
>
> hci0: Type: Primary Bus: USB
> BD Address: 00:1A:7D:DA:7X:XX ACL MTU: 679:8 SCO MTU: 48:16
> UP RUNNING PSCAN ISCAN
> Features: 0xbf 0x3e 0x4d 0xfa 0xdb 0x3d 0x7b 0xc7
> Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
> Link policy: RSWITCH SNIFF
> Link mode: PERIPHERAL ACCEPT
> Name: 'CSR8510 A10.'
> Class: 0x7c0104
> Service Classes: Rendering, Capturing, Object Transfer, Audio, Telephony
> Device Class: Computer, Desktop workstation
> HCI Version: 4.0 (0x6) Revision: 0x3120
> LMP Version: 4.0 (0x6) Subversion: 0x22bb
> Manufacturer: Cambridge Silicon Radio (10)
>
> As well as the `lsusb -vv -d 0a12:0001`:
>
> ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 224 Wireless
> bDeviceSubClass 1 Radio Frequency
> bDeviceProtocol 1 Bluetooth
> bMaxPacketSize0 64
> idVendor 0x0a12 Cambridge Silicon Radio, Ltd
> idProduct 0x0001 Bluetooth Dongle (HCI mode)
> bcdDevice 88.91
> iManufacturer 0
> iProduct 2 BT DONGLE10
> iSerial 0
> bNumConfigurations 1
>
> Also, changed the benign dmesg print that shows up whenever the
> generic force-suspend fails from bt_dev_err to bt_dev_warn;
> it's okay and done on a best-effort basis, not a problem
> if that does not work.
If there are more iterations, you might want to split that one into a
separate commit.
> Also, swapped the HCI subver and LMP subver numbers for the Barrot
> in the comment, which I copied wrong the last time around.
>
> Fixes: 81cac64ba258a ("Bluetooth: Deal with USB devices that are faking CSR vendor")
> Fixes: cde1a8a992875 ("Bluetooth: btusb: Fix and detect most of the Chinese Bluetooth controllers")
> Fixes: d74e0ae7e0303 ("Bluetooth: btusb: Fix detection of some fake CSR controllers with a bcdDevice val of 0x0134")
> Fixes: 0671c0662383e ("Bluetooth: btusb: Add workaround for remote-wakeup issues with Barrot 8041a02 fake CSR controllers")
> Fixes: f4292e2faf522 ("Bluetooth: btusb: Make the CSR clone chip force-suspend workaround more generic")
>
> https://bugzilla.kernel.org/show_bug.cgi?id=60824
The tags Link and BugLink exist (in `scripts/checkpatch.pl`), and you
might want to use these tags.
The bug report is from 2013 and talks about a regression upgrading from
Linux 3.9 to 3.11. Was the bug report repurposed, or is the original
issue also fixed by your change?
> https://gist.github.com/nevack/6b36b82d715dc025163d9e9124840a07
>
> Cc: stable@...r.kernel.org
> Cc: Hans de Goede <hdegoede@...hat.com>
> Tested-by: Gonzalo Tornaría <tornaria@...t.edu.uy>
> Tested-by: Mateus Lemos <lemonsmateus@...il.com>
> Tested-by: Ismael Ferreras Morezuelas <swyterzone@...il.com>
> Signed-off-by: Ismael Ferreras Morezuelas <swyterzone@...il.com>
> ---
>
> Changes for v2:
> * Added HCI_QUIRK_NO_SUSPEND_NOTIFIER to btusb_setup_csr().
> In theory we already disable runtime suspend in btusb, button
> better safe than sorry. Doesn't hurt to explicitly avoid the
> hci_suspend_dev() codepath, it also works as example.
> * Improved the quirk description in hci.h, as suggested by Hans
> de Goede. Explain the need to disable runtime suspend.
> * Also check for the quirk in hci_req_set_event_filter();
> mirror its hci_req_clear_event_filter() counterpart.
> * The struct hci_dev *hdev variables always go first.
> * Removed some misc formatting changes.
>
> The dongles still seem all peachy after the v2 changes. :)
>
> drivers/bluetooth/btusb.c | 6 ++++--
> include/net/bluetooth/hci.h | 10 ++++++++++
> net/bluetooth/hci_core.c | 11 ++++++++---
> net/bluetooth/hci_request.c | 13 ++++++++++---
> 4 files changed, 32 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 75c83768c..c3bfb9bbe 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -1932,6 +1932,8 @@ static int btusb_setup_csr(struct hci_dev *hdev)
> */
> set_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks);
> set_bit(HCI_QUIRK_BROKEN_ERR_DATA_REPORTING, &hdev->quirks);
> + set_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks);
> + set_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks);
>
> /* Clear the reset quirk since this is not an actual
> * early Bluetooth 1.1 device from CSR.
> @@ -1942,7 +1944,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
> /*
> * Special workaround for these BT 4.0 chip clones, and potentially more:
> *
> - * - 0x0134: a Barrot 8041a02 (HCI rev: 0x1012 sub: 0x0810)
> + * - 0x0134: a Barrot 8041a02 (HCI rev: 0x0810 sub: 0x1012)
> * - 0x7558: IC markings FR3191AHAL 749H15143 (HCI rev/sub-version: 0x0709)
> *
> * These controllers are really messed-up.
> @@ -1971,7 +1973,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
> if (ret >= 0)
> msleep(200);
> else
> - bt_dev_err(hdev, "CSR: Failed to suspend the device for our Barrot 8041a02 receive-issue workaround");
> + bt_dev_warn(hdev, "CSR: Couldn't suspend the device for our Barrot 8041a02 receive-issue workaround");
>
> pm_runtime_forbid(&data->udev->dev);
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 63065bc01..a17b8453a 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -246,6 +246,16 @@ enum {
> * HCI after resume.
> */
> HCI_QUIRK_NO_SUSPEND_NOTIFIER,
> +
> + /* When this quirk is set, HCI_OP_SET_EVENT_FLT requests with
> + * HCI_FLT_CLEAR_ALL are ignored and event filtering is
> + * completely avoided. A subset of the CSR controller
> + * clones struggle with this and instantly lock up.
> + *
> + * Note that devices using this must (separately) disable
> + * runtime suspend, because event filtering takes place there.
> + */
> + HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL,
> };
>
> /* HCI device flags */
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 8d33aa648..51d53c476 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -148,6 +148,7 @@ static int hci_init1_req(struct hci_request *req, unsigned long opt)
>
> static void bredr_setup(struct hci_request *req)
> {
> + struct hci_dev *hdev = req->hdev;
> __le16 param;
> __u8 flt_type;
>
> @@ -169,9 +170,13 @@ static void bredr_setup(struct hci_request *req)
> /* Read Current IAC LAP */
> hci_req_add(req, HCI_OP_READ_CURRENT_IAC_LAP, 0, NULL);
>
> - /* Clear Event Filters */
> - flt_type = HCI_FLT_CLEAR_ALL;
> - hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &flt_type);
> + /* Clear Event Filters; some fake CSR controllers lock up after setting
> + * this type of filter, so avoid sending the request altogether.
> + */
> + if (!test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks)) {
> + flt_type = HCI_FLT_CLEAR_ALL;
> + hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &flt_type);
> + }
>
> /* Connection accept timeout ~20 secs */
> param = cpu_to_le16(0x7d00);
> diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
> index 92611bfc0..c417325fe 100644
> --- a/net/bluetooth/hci_request.c
> +++ b/net/bluetooth/hci_request.c
> @@ -979,12 +979,16 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
>
> static void hci_req_clear_event_filter(struct hci_request *req)
> {
> + struct hci_dev *hdev = req->hdev;
> struct hci_cp_set_event_filter f;
>
> - if (!hci_dev_test_flag(req->hdev, HCI_BREDR_ENABLED))
> + if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
> + return;
> +
> + if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
> return;
>
> - if (hci_dev_test_flag(req->hdev, HCI_EVENT_FILTER_CONFIGURED)) {
> + if (hci_dev_test_flag(hdev, HCI_EVENT_FILTER_CONFIGURED)) {
> memset(&f, 0, sizeof(f));
> f.flt_type = HCI_FLT_CLEAR_ALL;
> hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &f);
> @@ -993,15 +997,18 @@ static void hci_req_clear_event_filter(struct hci_request *req)
>
> static void hci_req_set_event_filter(struct hci_request *req)
> {
> + struct hci_dev *hdev = req->hdev;
> struct bdaddr_list_with_flags *b;
> struct hci_cp_set_event_filter f;
> - struct hci_dev *hdev = req->hdev;
> u8 scan = SCAN_DISABLED;
> bool scanning = test_bit(HCI_PSCAN, &hdev->flags);
>
> if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
> return;
>
> + if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
> + return;
> +
> /* Always clear event filter when starting */
> hci_req_clear_event_filter(req);
>
Acked-by: Paul Menzel <pmenzel@...gen.mpg.de>
Kind regards,
Paul
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