Messages in this thread Patch in this message | | | Date | Thu, 29 Dec 2011 01:22:01 +0100 | From | Rene Herman <> | Subject | Re: [bluetooth] linux-3.x regression (bisected) |
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On 29-12-11 00:07, Marcel Holtmann wrote:
>> By the way, while the bluetooth (2.0) spec seems to consist of a 1230 >> page document that I am most certainly not going to study ... >> >> ... I couldn't help noticing that the HCI_Read_Local_Extended_Features >> command is in fact specified to return "The highest features page number >> which contains non-zero bits for the local device", and if I look at the >> above, it seems to indeed return max=0. >> >> Is it as such not in fact the case that the dongle is spec-compliant, >> whereas it's the linux code that neglects to check that return value in >> order to make sure that it requested a valid page? > > the Linux code indeed is broken for not checking the returned page, but > it is broken for different reasons. > > However the expected result from the dongle would be an error code and > not just returning page 0 instead.
Okay. Just as an additional data point:
I came across the HCI_Read_Local_Supported_Commands command in the spec a few pages up and quickly verified that the adapter doesn't in fact deny support for the HCI_Read_Local_Extended_Features command.
That is, after applying the below, I do get:
hci_cc_read_local_commands:hci0 status 0x0 hci_cc_read_local_commands:hci0 commands[14] 0xe8
which does claim support for the command (bit 6 of commands[14]).
Thought I'd check since if it hadn't, that would imply a certain fix but that can't be used then.
I'll stand by to test whatever final solution is arrived at.
(although I don't personally care, linux 3.0.y and 3.1.y may want it as well at that point I guess).
Rene.
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 8fe270c..0ac87ea 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -622,6 +622,7 @@ static void hci_cc_read_local_commands(struct hci_dev *hdev, struct sk_buff *skb goto done;
memcpy(hdev->commands, rp->commands, sizeof(hdev->commands)); + BT_DBG("%s commands[14] 0x%x", hdev->name, rp->commands[14]);
if (test_bit(HCI_INIT, &hdev->flags) && (hdev->commands[5] & 0x10)) hci_setup_link_policy(hdev);
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