Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.1 \(3445.4.7\)) Subject: Re: [RFC 1/9] Bluetooth: Read no of adv sets during init From: Marcel Holtmann In-Reply-To: Date: Fri, 8 Dec 2017 19:34:50 +0100 Cc: Luiz Augusto von Dentz , "linux-bluetooth@vger.kernel.org" , Jaganath Kanakkassery Message-Id: <516BE15C-ECD3-496B-AE6B-08E63F804F9F@holtmann.org> References: <1512374873-1956-1-git-send-email-jaganathx.kanakkassery@intel.com> <1512374873-1956-2-git-send-email-jaganathx.kanakkassery@intel.com> <68C5E7A6-B4A6-4EA9-BF40-9ACFDAAE7749@holtmann.org> To: Jaganath K Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Jaganath, >>>> This patch reads the number of advertising sets in the controller >>>> during init and save it in hdev. >>>> >>>> Currently host only supports upto HCI_MAX_ADV_INSTANCES (5). >>>> >>>> Instance 0 is reserved for "Set Advertising" which means that >>>> multi adv is supported only for total sets - 1. >>>> >>>> Signed-off-by: Jaganath Kanakkassery >>>> --- >>>> include/net/bluetooth/hci.h | 7 +++++++ >>>> include/net/bluetooth/hci_core.h | 4 ++++ >>>> net/bluetooth/hci_core.c | 11 +++++++++-- >>>> net/bluetooth/hci_event.c | 20 ++++++++++++++++++++ >>>> net/bluetooth/mgmt.c | 6 +++--- >>>> 5 files changed, 43 insertions(+), 5 deletions(-) >>>> >>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h >>>> index f0868df..59df823 100644 >>>> --- a/include/net/bluetooth/hci.h >>>> +++ b/include/net/bluetooth/hci.h >>>> @@ -398,6 +398,7 @@ enum { >>>> #define HCI_LE_SLAVE_FEATURES 0x08 >>>> #define HCI_LE_PING 0x10 >>>> #define HCI_LE_DATA_LEN_EXT 0x20 >>>> +#define HCI_LE_EXT_ADV 0x10 >>>> #define HCI_LE_EXT_SCAN_POLICY 0x80 >>>> >>>> /* Connection modes */ >>>> @@ -1543,6 +1544,12 @@ struct hci_cp_le_ext_conn_param { >>>> __le16 max_ce_len; >>>> } __packed; >>>> >>>> +#define HCI_OP_LE_READ_NUM_SUPPORTED_ADV_SETS 0x203b >>>> +struct hci_rp_le_read_num_supported_adv_sets { >>>> + __u8 status; >>>> + __u8 num_of_sets; >>>> +} __packed; >>>> + >>>> /* ---- HCI Events ---- */ >>>> #define HCI_EV_INQUIRY_COMPLETE 0x01 >>>> >>>> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h >>>> index 554671c..4a7a4ae 100644 >>>> --- a/include/net/bluetooth/hci_core.h >>>> +++ b/include/net/bluetooth/hci_core.h >>>> @@ -219,6 +219,7 @@ struct hci_dev { >>>> __u8 features[HCI_MAX_PAGES][8]; >>>> __u8 le_features[8]; >>>> __u8 le_white_list_size; >>>> + __u8 le_no_of_adv_sets; >>> >>> I was expecting some flag that indicates if the instances would be >>> maintained by the controller or not, but perhaps this is covered in >>> other patches. >>> >>>> __u8 le_states[8]; >>>> __u8 commands[64]; >>>> __u8 hci_ver; >>>> @@ -1154,6 +1155,9 @@ void hci_conn_del_sysfs(struct hci_conn *conn); >>>> #define bredr_sc_enabled(dev) (lmp_sc_capable(dev) && \ >>>> hci_dev_test_flag(dev, HCI_SC_ENABLED)) >>>> >>>> +/* Extended advertising support */ >>>> +#define ext_adv_capable(dev) ((dev)->le_features[1] & HCI_LE_EXT_ADV) >>>> + >>>> /* ----- HCI protocols ----- */ >>>> #define HCI_PROTO_DEFER 0x01 >>>> >>>> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c >>>> index a91a09a..3472572 100644 >>>> --- a/net/bluetooth/hci_core.c >>>> +++ b/net/bluetooth/hci_core.c >>>> @@ -716,6 +716,12 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt) >>>> hci_req_add(req, HCI_OP_LE_READ_DEF_DATA_LEN, 0, NULL); >>>> } >>>> >>>> + if (ext_adv_capable(hdev)) { >>>> + /* Read LE Number of Supported Advertising Sets */ >>>> + hci_req_add(req, HCI_OP_LE_READ_NUM_SUPPORTED_ADV_SETS, >>>> + 0, NULL); >>>> + } >>>> + >>>> hci_set_le_support(req); >>>> } >>>> >>>> @@ -2676,8 +2682,8 @@ int hci_add_adv_instance(struct hci_dev *hdev, u8 instance, u32 flags, >>>> memset(adv_instance->scan_rsp_data, 0, >>>> sizeof(adv_instance->scan_rsp_data)); >>>> } else { >>>> - if (hdev->adv_instance_cnt >= HCI_MAX_ADV_INSTANCES || >>>> - instance < 1 || instance > HCI_MAX_ADV_INSTANCES) >>>> + if (hdev->adv_instance_cnt >= hdev->le_no_of_adv_sets || >>>> + instance < 1 || instance > hdev->le_no_of_adv_sets) >>>> return -EOVERFLOW; >>>> >>>> adv_instance = kzalloc(sizeof(*adv_instance), GFP_KERNEL); >>>> @@ -2972,6 +2978,7 @@ struct hci_dev *hci_alloc_dev(void) >>>> hdev->le_max_tx_time = 0x0148; >>>> hdev->le_max_rx_len = 0x001b; >>>> hdev->le_max_rx_time = 0x0148; >>>> + hdev->le_no_of_adv_sets = HCI_MAX_ADV_INSTANCES; >>>> >>>> hdev->rpa_timeout = HCI_DEFAULT_RPA_TIMEOUT; >>>> hdev->discov_interleaved_timeout = DISCOV_INTERLEAVED_TIMEOUT; >>>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c >>>> index a26ae80..06d8c1b 100644 >>>> --- a/net/bluetooth/hci_event.c >>>> +++ b/net/bluetooth/hci_event.c >>>> @@ -1243,6 +1243,22 @@ static void hci_cc_le_set_ext_scan_enable(struct hci_dev *hdev, >>>> le_set_scan_enable_complete(hdev, cp->enable); >>>> } >>>> >>>> +static void hci_cc_le_read_num_adv_sets(struct hci_dev *hdev, >>>> + struct sk_buff *skb) >>>> +{ >>>> + struct hci_rp_le_read_num_supported_adv_sets *rp = (void *) skb->data; >>>> + >>>> + BT_DBG("%s status 0x%2.2x No of Adv sets %u", hdev->name, rp->status, >>>> + rp->num_of_sets); >>>> + >>>> + if (rp->status) >>>> + return; >>>> + >>>> + /* Instance 0 is reserved for Set Advertising */ >>>> + hdev->le_no_of_adv_sets = min_t(u8, rp->num_of_sets - 1, >>>> + HCI_MAX_ADV_INSTANCES); >>> >>> Id say if the controller cannot support as many instances as the host >>> stack then we should keep using the software based scheduler, another >>> option would be to let the user select what scheduler it wants to use >>> since with host based scheduler it may get a much more consistent >>> behavior than with controller based which is especially important for >>> beacons. >> >> frankly this will not help either. The max instances reported from the controller is not a fixed guaranteed number. It is the most likely case. However a controller can run out of resources and decide to refuse an advertising instance. >> > > Does it mean that we need to retrieve no of supported adv sets every time > we enable advertising? > > or try enabling based on the initial no_of_sets and handle it for eg > if adv_set_param > failed with "Limit Reached" error? we need to handle the error case correctly. >> However having an extra flag for permanent / continuous offload would be interesting. If not specified, then the kernel will rotate. For 4.x controllers it will rotate based on a single instance, for 5.x it will rotate with n instances. The extra flag could then indicate, please do not include me into the rotation and keep me always active. Which is something that instance 0 would always inherit. >> > > So you want to still rotate adv instances by kernel wherein at a time > n adv sets/instances > would be enabled, where n is no of supported sets? and timer should be > running for the > min of scheduled adv instances duration and once timer expires then > replace it with the > next unscheduled instance. It would be some sort of round-robin. If we have more instances than sets, then timer has to run, and then we rotate, the oldest one moves out, the next moves in. Regards Marcel