diff mbox series

Bluetooth: add quirk disabling query LE tx power

Message ID 20210930141256.19943-1-redecorating@protonmail.com (mailing list archive)
State Superseded, archived
Headers show
Series Bluetooth: add quirk disabling query LE tx power | expand

Checks

Context Check Description
tedd_an/checkpatch fail Bluetooth: add quirk disabling query LE tx power\CHECK:PARENTHESIS_ALIGNMENT: Alignment should match open parenthesis #110: FILE: net/bluetooth/hci_core.c:746: + if (hdev->commands[38] & 0x80 && + !test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks)) { total: 0 errors, 0 warnings, 1 checks, 33 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. /github/workspace/src/12528487.patch has style problems, please review. NOTE: Ignored message types: UNKNOWN_COMMIT_ID NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS.
tedd_an/gitlint success Gitlint PASS
tedd_an/buildkernel success Build Kernel PASS
tedd_an/testrunnersetup fail Test Runner Setup BlueZ FAIL

Commit Message

Orlando Chamberlain Sept. 30, 2021, 2:13 p.m. UTC
Querying LE tx power on startup broke Bluetooth on some Broadcom chips
in Apple computers (at least MacBookPro16,1 and iMac20,1). Added a quirk
disabling this query for affected devices, based off their common chip
id 150. Affected devices will not be able to query LE tx power, however
they were not doing this before.

Fixes: 7c395ea521e6m ("Bluetooth: Query LE tx power on startup")
Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com>
---
 drivers/bluetooth/btbcm.c   | 4 ++++
 include/net/bluetooth/hci.h | 8 ++++++++
 net/bluetooth/hci_core.c    | 3 ++-
 3 files changed, 14 insertions(+), 1 deletion(-)

Comments

Thorsten Leemhuis Sept. 30, 2021, 5:03 p.m. UTC | #1
On 30.09.21 16:13, Orlando Chamberlain wrote:
> Querying LE tx power on startup broke Bluetooth on some Broadcom chips
> in Apple computers (at least MacBookPro16,1 and iMac20,1). Added a quirk
> disabling this query for affected devices, based off their common chip
> id 150. Affected devices will not be able to query LE tx power, however
> they were not doing this before.
> 
> Fixes: 7c395ea521e6m ("Bluetooth: Query LE tx power on startup")
> Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com>

FWIW, if you need to respin this for some reason, could you do me a
favour and add the following after the "Fixes" line please:

Link:
https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@protonmail.com

That makes is easier to find related discussions and rationale behind a
certain change, as explained here:
https://www.kernel.org/doc/html/latest/maintainer/configure-git.html

This line is not crucial, but it makes my life easier as well, as I
slowly start to track regressions again. And this time I'm doing it with
the help of a software I wrote just for this purpose. I used your report
as one of the first few to give this "regzbot" a test, hence the issue
can now be seen in the webinterface (which is still a bit ugly, but it
does the job):

https://linux-regtracking.leemhuis.info/regzbot/mainline.html

And the thing is: when regzbot sees a patch with above Link:-tag hit
mainline it will automatically mark the issue as resolved, saving me
some work.

Thx!

Ciao, Thorsten
Marcel Holtmann Sept. 30, 2021, 5:58 p.m. UTC | #2
Hi Orlando,

> Querying LE tx power on startup broke Bluetooth on some Broadcom chips
> in Apple computers (at least MacBookPro16,1 and iMac20,1). Added a quirk
> disabling this query for affected devices, based off their common chip
> id 150. Affected devices will not be able to query LE tx power, however
> they were not doing this before.
> 
> Fixes: 7c395ea521e6m ("Bluetooth: Query LE tx power on startup")
> Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com>
> ---
> drivers/bluetooth/btbcm.c   | 4 ++++
> include/net/bluetooth/hci.h | 8 ++++++++
> net/bluetooth/hci_core.c    | 3 ++-
> 3 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
> index e4182acee488..4ecc50d93107 100644
> --- a/drivers/bluetooth/btbcm.c
> +++ b/drivers/bluetooth/btbcm.c
> @@ -353,6 +353,10 @@ static int btbcm_read_info(struct hci_dev *hdev)
> 		return PTR_ERR(skb);
> 
> 	bt_dev_info(hdev, "BCM: chip id %u", skb->data[1]);
> +
> +	if (skb->data[1] == 150)
> +		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
> +
> 	kfree_skb(skb);
> 
> 	/* Read Controller Features */
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index b80415011dcd..5e0dd0c39ade 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -246,6 +246,14 @@ enum {
> 	 * HCI after resume.
> 	 */
> 	HCI_QUIRK_NO_SUSPEND_NOTIFIER,
> +
> +	/*
> +	 * When this quirk is set, LE tx power is not queried on startup.
> +	 *
> +	 * This quirk can be set before hci_register_dev is called or
> +	 * during the hdev->setup vendor callback.
> +	 */
> +	HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
> };
> 
> /* HCI device flags */
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 8a47a3017d61..16e39739c662 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -742,7 +742,8 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt)
> 			hci_req_add(req, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL);
> 		}
> 
> -		if (hdev->commands[38] & 0x80) {
> +		if (hdev->commands[38] & 0x80 &&
> +			!test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks)) {
> 			/* Read LE Min/Max Tx Power*/
> 			hci_req_add(req, HCI_OP_LE_READ_TRANSMIT_POWER,
> 				    0, NULL);

so I really need the btmon traces from the device init (so unload and reload the module) and we need to see what commands are supported and what commands are failing.

Since you say this is on a MacBook, I assume this is an UART based Broadcom chip. Sometimes Broadcom has been really flaky with their actually implemented commands. However in some cases firmware updates do fix this. So any chance you can boot OS X and check that the latest firmware is loaded.

Regards

Marcel
Orlando Chamberlain Oct. 1, 2021, 3:37 a.m. UTC | #3
On 1/10/21 03:58, Marcel Holtmann wrote:
> so I really need the btmon traces from the device init (so unload and reload the module) and we need to see what commands are supported and what commands are failing.
I'll attach the full file I got with btmon -w MacBookPro16,1.btsnoop, but these seem
like the important bits:

< HCI Command: Read Local Supported Commands (0x04|0x0002) plen 0	#43 [hci0] 9.217379

> HCI Event: Command Complete (0x0e) plen 68				#44 [hci0] 9.218033

      Read Local Supported Commands (0x04|0x0002) ncmd 1

        Status: Success (0x00)

        Commands: 223 entries
	## many many lines here ##
	LE Read Transmit Power (Octet 38 - Bit 7)
	LE Read RF Path Compensation (Octet 39 - Bit 0)

	LE Write RF Path Compensation (Octet 39 - Bit 1)

	LE Set Privacy Mode (Octet 39 - Bit 2)

	Read Local Simple Pairing Options (Octet 41 - Bit 

At the end of the trace:

< HCI Command: LE Read Transmit Power (0x08|0x004b) plen 0		#69 [hci0] 9.226953
> HCI Event: Command Complete (0x0e) plen 4				#70 [hci0] 9.227515
      LE Read Transmit Power (0x08|0x004b) ncmd 1
        Status: Unknown HCI Command (0x01)
= Close Index: F8:FF:C2:06:46:63					[hci0] 9.227666

I'm guessing that this means it reports that it supports the command but it doesn't,
so if this is the case, I'd have to change the description of the quirk to clarify that.

> Since you say this is on a MacBook, I assume this is an UART based Broadcom chip. Sometimes Broadcom has been really flaky with their actually implemented commands. However in some cases firmware updates do fix this. So any chance you can boot OS X and check that the latest firmware is loaded.

Bluetooth for this device is indeed through uart:

# lspci -vvvnnd '8086:a328'
00:1e.0 Communication controller [0780]: Intel Corporation Cannon Lake PCH Serial IO UART Host Controller    [8086:a328] (rev 10)

    Subsystem: Intel Corporation Device [8086:7270]

    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-

    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-

    Latency: 0, Cache Line Size: 256 bytes

    Interrupt: pin A routed to IRQ 20

    IOMMU group: 8

    Region 0: Memory at 4000000000 (64-bit, non-prefetchable) [size=4K]

    Capabilities: [80] Power Management version 3

        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)

        Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-

    Capabilities: [90] Vendor Specific Information: Len=14 <?>

    Kernel driver in use: intel-lpss

    Kernel modules: intel_lpss_pci

$ cat /sys/bus/pci/devices/0000:00:1e.0/dw-apb-uart.0/serial0/serial0-0/modalias

acpi:BCM2E7C:APPLE-UART-BLTH:

I've just updated macOS to 11.6, which should have updated firmware. The issue is still present.
diff mbox series

Patch

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index e4182acee488..4ecc50d93107 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -353,6 +353,10 @@  static int btbcm_read_info(struct hci_dev *hdev)
 		return PTR_ERR(skb);
 
 	bt_dev_info(hdev, "BCM: chip id %u", skb->data[1]);
+
+	if (skb->data[1] == 150)
+		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
+
 	kfree_skb(skb);
 
 	/* Read Controller Features */
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index b80415011dcd..5e0dd0c39ade 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -246,6 +246,14 @@  enum {
 	 * HCI after resume.
 	 */
 	HCI_QUIRK_NO_SUSPEND_NOTIFIER,
+
+	/*
+	 * When this quirk is set, LE tx power is not queried on startup.
+	 *
+	 * This quirk can be set before hci_register_dev is called or
+	 * during the hdev->setup vendor callback.
+	 */
+	HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
 };
 
 /* HCI device flags */
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 8a47a3017d61..16e39739c662 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -742,7 +742,8 @@  static int hci_init3_req(struct hci_request *req, unsigned long opt)
 			hci_req_add(req, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL);
 		}
 
-		if (hdev->commands[38] & 0x80) {
+		if (hdev->commands[38] & 0x80 &&
+			!test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks)) {
 			/* Read LE Min/Max Tx Power*/
 			hci_req_add(req, HCI_OP_LE_READ_TRANSMIT_POWER,
 				    0, NULL);