[PATCH] Bluetooth: hci_core: Fix attempting to set RPA timeout when unsupported

[PATCH] Bluetooth: hci_core: Fix attempting to set RPA timeout when unsupported

[Edward Vear]

During controller initialization, an LE Set RPA Timeout command is sent
to the controller if supported. However, the value checked to determine
if the command is supported is incorrect. Page 1921 of the Bluetooth
Core Spec v5.2 shows that bit 2 of octet 35 of the Supported_Commands
field corresponds to the LE Set RPA Timeout command, but currently
bit 6 of octet 35 is checked. This patch checks the correct value
instead.

This issue led to the error seen in the following btmon output during
initialization of an adapter (rtl8761b) and prevented initialization
from completing.

< HCI Command: LE Set Resolvable Private Address Timeout (0x08|0x002e) plen 2
        Timeout: 900 seconds
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Resolvable Private Address Timeout (0x08|0x002e) ncmd 2
        Status: Unsupported Remote Feature / Unsupported LMP Feature (0x1a)
= Close Index: 00:E0:4C:6B:E5:03

The error did not appear when running with this patch.

Signed-off-by: Edward Vear <edwardvear@gmail.com>
---
 net/bluetooth/hci_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 502552d6e9af..c4aa2cbb9269 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -763,7 +763,7 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt)
 			hci_req_add(req, HCI_OP_LE_CLEAR_RESOLV_LIST, 0, NULL);
 		}
 
-		if (hdev->commands[35] & 0x40) {
+		if (hdev->commands[35] & 0x04) {
 			__le16 rpa_timeout = cpu_to_le16(hdev->rpa_timeout);
 
 			/* Set RPA timeout */
-- 
2.29.1

Re: [PATCH] Bluetooth: hci_core: Fix attempting to set RPA timeout when unsupported

[Edward Vear]

Just following up on this. It appears several people have had success
using this patch to get their bluetooth devices working:
https://bugzilla.kernel.org/show_bug.cgi?id=208965. Is there anything
else I should include?

Best,
Edward


On Tue, Oct 27, 2020 at 12:03 AM Edward Vear <edwardvear@gmail.com> wrote:
>
> During controller initialization, an LE Set RPA Timeout command is sent
> to the controller if supported. However, the value checked to determine
> if the command is supported is incorrect. Page 1921 of the Bluetooth
> Core Spec v5.2 shows that bit 2 of octet 35 of the Supported_Commands
> field corresponds to the LE Set RPA Timeout command, but currently
> bit 6 of octet 35 is checked. This patch checks the correct value
> instead.
>
> This issue led to the error seen in the following btmon output during
> initialization of an adapter (rtl8761b) and prevented initialization
> from completing.
>
> < HCI Command: LE Set Resolvable Private Address Timeout (0x08|0x002e) plen 2
>         Timeout: 900 seconds
> > HCI Event: Command Complete (0x0e) plen 4
>       LE Set Resolvable Private Address Timeout (0x08|0x002e) ncmd 2
>         Status: Unsupported Remote Feature / Unsupported LMP Feature (0x1a)
> = Close Index: 00:E0:4C:6B:E5:03
>
> The error did not appear when running with this patch.
>
> Signed-off-by: Edward Vear <edwardvear@gmail.com>
> ---
>  net/bluetooth/hci_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 502552d6e9af..c4aa2cbb9269 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -763,7 +763,7 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt)
>                         hci_req_add(req, HCI_OP_LE_CLEAR_RESOLV_LIST, 0, NULL);
>                 }
>
> -               if (hdev->commands[35] & 0x40) {
> +               if (hdev->commands[35] & 0x04) {
>                         __le16 rpa_timeout = cpu_to_le16(hdev->rpa_timeout);
>
>                         /* Set RPA timeout */
> --
> 2.29.1
>

Re: [PATCH] Bluetooth: hci_core: Fix attempting to set RPA timeout when unsupported

[Marcel Holtmann]

Hi Edward,

> During controller initialization, an LE Set RPA Timeout command is sent
> to the controller if supported. However, the value checked to determine
> if the command is supported is incorrect. Page 1921 of the Bluetooth
> Core Spec v5.2 shows that bit 2 of octet 35 of the Supported_Commands
> field corresponds to the LE Set RPA Timeout command, but currently
> bit 6 of octet 35 is checked. This patch checks the correct value
> instead.
> 
> This issue led to the error seen in the following btmon output during
> initialization of an adapter (rtl8761b) and prevented initialization
> from completing.
> 
> < HCI Command: LE Set Resolvable Private Address Timeout (0x08|0x002e) plen 2
>        Timeout: 900 seconds
>> HCI Event: Command Complete (0x0e) plen 4
>      LE Set Resolvable Private Address Timeout (0x08|0x002e) ncmd 2
>        Status: Unsupported Remote Feature / Unsupported LMP Feature (0x1a)
> = Close Index: 00:E0:4C:6B:E5:03
> 
> The error did not appear when running with this patch.
> 
> Signed-off-by: Edward Vear <edwardvear@gmail.com>
> ---
> net/bluetooth/hci_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel