diff mbox series

Bluetooth: btqcomsmd: Fix command timeout after setting BD address

Message ID 20220613110745.3778356-1-stephan.gerhold@kernkonzept.com (mailing list archive)
State Superseded
Headers show
Series Bluetooth: btqcomsmd: Fix command timeout after setting BD address | expand

Checks

Context Check Description
tedd_an/pre-ci_am success Success
tedd_an/checkpatch success Checkpatch PASS
tedd_an/gitlint fail Bluetooth: btqcomsmd: Fix command timeout after setting BD address 8: B3 Line contains hard tab characters (\t): " Bluetooth: hci0: Opcode 0x c03 failed: -110"
tedd_an/subjectprefix success PASS
tedd_an/buildkernel success Build Kernel PASS
tedd_an/buildkernel32 success Build Kernel32 PASS
tedd_an/incremental_build success Pass
tedd_an/testrunnersetup success Test Runner Setup PASS
tedd_an/testrunnerl2cap-tester success Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnerbnep-tester success Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnermgmt-tester fail Total: 493, Passed: 491 (99.6%), Failed: 2, Not Run: 0
tedd_an/testrunnerrfcomm-tester success Total: 10, Passed: 10 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnersco-tester success Total: 12, Passed: 12 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnersmp-tester success Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunneruserchan-tester success Total: 4, Passed: 4 (100.0%), Failed: 0, Not Run: 0

Commit Message

Stephan Gerhold June 13, 2022, 11:07 a.m. UTC
The Bluetooth firmware seems to become unresponsive for a while after
setting the BD address. At least on recent kernel versions this often
causes timeouts for subsequent commands, e.g. the HCI reset sent by
the Bluetooth core during initialization:

	Bluetooth: hci0: Opcode 0x c03 failed: -110

Unfortunately this behavior does not seem to be documented anywhere.
Experimentation suggests that the minimum necessary delay to avoid
the problem is ~150us. However, to be sure add a sleep for > 1ms
in case it is a bit longer on other firmware versions.

Fixes: 1511cc750c3d ("Bluetooth: Introduce Qualcomm WCNSS SMD based HCI driver")
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
---
I tested this using a script that reboots repeatedly and checks for the
error. With this patch, BT shows up successfully for 100+ consecutive
boots. Without this patch it usually fails after 1-5 boots (or even
always on some boards).
---
 drivers/bluetooth/btqcomsmd.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Comments

Paul Menzel June 13, 2022, 4:09 p.m. UTC | #1
Dear Stephan,


Thank you for the patch.

Am 13.06.22 um 13:07 schrieb Stephan Gerhold:
> The Bluetooth firmware seems to become unresponsive for a while after

Please mention the device with the problematic firmware.

> setting the BD address. At least on recent kernel versions this often

The commit referenced in the Fixes tag is in Linux 4.9. Can you please 
name the oldest Linux kernel version you experienced the problem with.

> causes timeouts for subsequent commands, e.g. the HCI reset sent by
> the Bluetooth core during initialization:
> 
> 	Bluetooth: hci0: Opcode 0x c03 failed: -110
> 
> Unfortunately this behavior does not seem to be documented anywhere.
> Experimentation suggests that the minimum necessary delay to avoid
> the problem is ~150us. However, to be sure add a sleep for > 1ms
> in case it is a bit longer on other firmware versions.
> 
> Fixes: 1511cc750c3d ("Bluetooth: Introduce Qualcomm WCNSS SMD based HCI driver")
> Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
> ---
> I tested this using a script that reboots repeatedly and checks for the
> error. With this patch, BT shows up successfully for 100+ consecutive
> boots. Without this patch it usually fails after 1-5 boots (or even
> always on some boards).
> ---
>   drivers/bluetooth/btqcomsmd.c | 17 ++++++++++++++++-
>   1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bluetooth/btqcomsmd.c b/drivers/bluetooth/btqcomsmd.c
> index 2acb719e596f..11c7e04bf394 100644
> --- a/drivers/bluetooth/btqcomsmd.c
> +++ b/drivers/bluetooth/btqcomsmd.c
> @@ -122,6 +122,21 @@ static int btqcomsmd_setup(struct hci_dev *hdev)
>   	return 0;
>   }
>   
> +static int btqcomsmd_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
> +{
> +	int ret;
> +
> +	ret = qca_set_bdaddr_rome(hdev, bdaddr);
> +	if (ret)
> +		return ret;
> +
> +	/* The firmware stops responding for a while after setting the bdaddr,
> +	 * causing timeouts for subsequent commands. Sleep a bit to avoid this.
> +	 */
> +	usleep_range(1000, 10000);
> +	return 0;
> +}
> +
>   static int btqcomsmd_probe(struct platform_device *pdev)
>   {
>   	struct btqcomsmd *btq;
> @@ -162,7 +177,7 @@ static int btqcomsmd_probe(struct platform_device *pdev)
>   	hdev->close = btqcomsmd_close;
>   	hdev->send = btqcomsmd_send;
>   	hdev->setup = btqcomsmd_setup;
> -	hdev->set_bdaddr = qca_set_bdaddr_rome;
> +	hdev->set_bdaddr = btqcomsmd_set_bdaddr;
>   
>   	ret = hci_register_dev(hdev);
>   	if (ret < 0)


Kind regards,

Paul
bluez.test.bot@gmail.com June 13, 2022, 4:14 p.m. UTC | #2
This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=649852

---Test result---

Test Summary:
CheckPatch                    PASS      1.62 seconds
GitLint                       FAIL      1.00 seconds
SubjectPrefix                 PASS      0.92 seconds
BuildKernel                   PASS      32.35 seconds
BuildKernel32                 PASS      28.92 seconds
Incremental Build with patchesPASS      39.04 seconds
TestRunner: Setup             PASS      476.76 seconds
TestRunner: l2cap-tester      PASS      17.37 seconds
TestRunner: bnep-tester       PASS      6.07 seconds
TestRunner: mgmt-tester       FAIL      105.82 seconds
TestRunner: rfcomm-tester     PASS      9.67 seconds
TestRunner: sco-tester        PASS      9.39 seconds
TestRunner: smp-tester        PASS      9.40 seconds
TestRunner: userchan-tester   PASS      6.37 seconds

Details
##############################
Test: GitLint - FAIL - 1.00 seconds
Run gitlint with rule in .gitlint
Bluetooth: btqcomsmd: Fix command timeout after setting BD address
8: B3 Line contains hard tab characters (\t): "	Bluetooth: hci0: Opcode 0x c03 failed: -110"


##############################
Test: TestRunner: mgmt-tester - FAIL - 105.82 seconds
Run test-runner with mgmt-tester
Total: 493, Passed: 491 (99.6%), Failed: 2, Not Run: 0

Failed Test Cases
Add Advertising - Success (Name+data+appear)         Timed out    2.630 seconds
Add Ext Advertising - Success (Name+data+appear)     Timed out    2.489 seconds



---
Regards,
Linux Bluetooth
Stephan Gerhold June 14, 2022, 8:02 a.m. UTC | #3
Hi Paul,

On Mon, Jun 13, 2022 at 06:09:33PM +0200, Paul Menzel wrote:
> Am 13.06.22 um 13:07 schrieb Stephan Gerhold:
> > The Bluetooth firmware seems to become unresponsive for a while after
> 
> Please mention the device with the problematic firmware.
> 

Will add a comment in v2. It seems to affect pretty much all devices
that make use of the "btqcomsmd" driver.

> > setting the BD address. At least on recent kernel versions this often
> 
> The commit referenced in the Fixes tag is in Linux 4.9. Can you please name
> the oldest Linux kernel version you experienced the problem with.
> 

This is quite hard to say. It definitely became more apparent in the
last few months (so at least 5.17+). But since it's a timing problem
it's influenced by various side effects. For example, it is less likely
to happen the more hardware functionality you enable on a board (because
other interrupts come in and might cause the necessary delay).

I believe that the problem also exists in some form on Linux 4.9,
even though it might be harder to trigger it there.

Thanks,
Stephan
diff mbox series

Patch

diff --git a/drivers/bluetooth/btqcomsmd.c b/drivers/bluetooth/btqcomsmd.c
index 2acb719e596f..11c7e04bf394 100644
--- a/drivers/bluetooth/btqcomsmd.c
+++ b/drivers/bluetooth/btqcomsmd.c
@@ -122,6 +122,21 @@  static int btqcomsmd_setup(struct hci_dev *hdev)
 	return 0;
 }
 
+static int btqcomsmd_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
+{
+	int ret;
+
+	ret = qca_set_bdaddr_rome(hdev, bdaddr);
+	if (ret)
+		return ret;
+
+	/* The firmware stops responding for a while after setting the bdaddr,
+	 * causing timeouts for subsequent commands. Sleep a bit to avoid this.
+	 */
+	usleep_range(1000, 10000);
+	return 0;
+}
+
 static int btqcomsmd_probe(struct platform_device *pdev)
 {
 	struct btqcomsmd *btq;
@@ -162,7 +177,7 @@  static int btqcomsmd_probe(struct platform_device *pdev)
 	hdev->close = btqcomsmd_close;
 	hdev->send = btqcomsmd_send;
 	hdev->setup = btqcomsmd_setup;
-	hdev->set_bdaddr = qca_set_bdaddr_rome;
+	hdev->set_bdaddr = btqcomsmd_set_bdaddr;
 
 	ret = hci_register_dev(hdev);
 	if (ret < 0)