Add support for CQM RSSI measurement reporting and advertise the
NL80211_EXT_FEATURE_CQM_RSSI_LIST feature. This enables a userspace
supplicant such as iwd to be notified of changes in the RSSI for roaming
and signal monitoring purposes.
Signed-off-by: Alvin Šipraga <[email protected]>
---
v1 -> v2:
- clarify firmware behaviour in a comment
- fix detection of upper bound RSSI transition
- improve clamping of min/max RSSI values
- remove unnecessary check on last RSSI value
---
.../broadcom/brcm80211/brcmfmac/cfg80211.c | 87 +++++++++++++++++++
.../broadcom/brcm80211/brcmfmac/cfg80211.h | 6 ++
.../broadcom/brcm80211/brcmfmac/fwil_types.h | 28 ++++++
3 files changed, 121 insertions(+)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 0ee421f30aa2..605aa3f4ddc7 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -5196,6 +5196,48 @@ brcmf_cfg80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
return err;
}
+static int brcmf_cfg80211_set_cqm_rssi_range_config(struct wiphy *wiphy,
+ struct net_device *ndev,
+ s32 rssi_low, s32 rssi_high)
+{
+ struct brcmf_cfg80211_vif *vif;
+ struct brcmf_if *ifp;
+ int err = 0;
+
+ brcmf_dbg(TRACE, "low=%d high=%d", rssi_low, rssi_high);
+
+ ifp = netdev_priv(ndev);
+ vif = ifp->vif;
+
+ if (rssi_low != vif->cqm_rssi_low || rssi_high != vif->cqm_rssi_high) {
+ /* The firmware will send an event when the RSSI is less than or
+ * equal to a configured level and the previous RSSI event was
+ * less than or equal to a different level. Set a third level
+ * so that we also detect the transition from rssi <= rssi_high
+ * to rssi > rssi_high.
+ */
+ struct brcmf_rssi_event_le config = {
+ .rate_limit_msec = cpu_to_le32(0),
+ .rssi_level_num = 3,
+ .rssi_levels = {
+ clamp_val(rssi_low, S8_MIN, S8_MAX - 2),
+ clamp_val(rssi_high, S8_MIN + 1, S8_MAX - 1),
+ S8_MAX,
+ },
+ };
+
+ err = brcmf_fil_iovar_data_set(ifp, "rssi_event", &config,
+ sizeof(config));
+ if (err) {
+ err = -EINVAL;
+ } else {
+ vif->cqm_rssi_low = rssi_low;
+ vif->cqm_rssi_high = rssi_high;
+ }
+ }
+
+ return err;
+}
static int
brcmf_cfg80211_cancel_remain_on_channel(struct wiphy *wiphy,
@@ -5502,6 +5544,7 @@ static struct cfg80211_ops brcmf_cfg80211_ops = {
.update_mgmt_frame_registrations =
brcmf_cfg80211_update_mgmt_frame_registrations,
.mgmt_tx = brcmf_cfg80211_mgmt_tx,
+ .set_cqm_rssi_range_config = brcmf_cfg80211_set_cqm_rssi_range_config,
.remain_on_channel = brcmf_p2p_remain_on_channel,
.cancel_remain_on_channel = brcmf_cfg80211_cancel_remain_on_channel,
.get_channel = brcmf_cfg80211_get_channel,
@@ -6137,6 +6180,47 @@ brcmf_notify_mic_status(struct brcmf_if *ifp,
return 0;
}
+static s32 brcmf_notify_rssi(struct brcmf_if *ifp,
+ const struct brcmf_event_msg *e, void *data)
+{
+ struct brcmf_cfg80211_vif *vif = ifp->vif;
+ struct brcmf_rssi_be *info = data;
+ s32 rssi, snr, noise;
+ s32 low, high, last;
+
+ if (e->datalen < sizeof(*info)) {
+ brcmf_err("insufficient RSSI event data\n");
+ return 0;
+ }
+
+ rssi = be32_to_cpu(info->rssi);
+ snr = be32_to_cpu(info->snr);
+ noise = be32_to_cpu(info->noise);
+
+ low = vif->cqm_rssi_low;
+ high = vif->cqm_rssi_high;
+ last = vif->cqm_rssi_last;
+
+ brcmf_dbg(TRACE, "rssi=%d snr=%d noise=%d low=%d high=%d last=%d\n",
+ rssi, snr, noise, low, high, last);
+
+ vif->cqm_rssi_last = rssi;
+
+ if (rssi <= low || rssi == 0) {
+ brcmf_dbg(INFO, "LOW rssi=%d\n", rssi);
+ cfg80211_cqm_rssi_notify(ifp->ndev,
+ NL80211_CQM_RSSI_THRESHOLD_EVENT_LOW,
+ rssi, GFP_KERNEL);
+ } else if (rssi > high) {
+ brcmf_dbg(INFO, "HIGH rssi=%d\n", rssi);
+ cfg80211_cqm_rssi_notify(ifp->ndev,
+ NL80211_CQM_RSSI_THRESHOLD_EVENT_HIGH,
+ rssi, GFP_KERNEL);
+ }
+
+ return 0;
+}
+
static s32 brcmf_notify_vif_event(struct brcmf_if *ifp,
const struct brcmf_event_msg *e, void *data)
{
@@ -6235,6 +6319,7 @@ static void brcmf_register_event_handlers(struct brcmf_cfg80211_info *cfg)
brcmf_p2p_notify_action_tx_complete);
brcmf_fweh_register(cfg->pub, BRCMF_E_PSK_SUP,
brcmf_notify_connect_status);
+ brcmf_fweh_register(cfg->pub, BRCMF_E_RSSI, brcmf_notify_rssi);
}
static void brcmf_deinit_priv_mem(struct brcmf_cfg80211_info *cfg)
@@ -7169,6 +7254,8 @@ static int brcmf_setup_wiphy(struct wiphy *wiphy, struct brcmf_if *ifp)
wiphy_ext_feature_set(wiphy,
NL80211_EXT_FEATURE_DFS_OFFLOAD);
+ wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_CQM_RSSI_LIST);
+
wiphy_read_of_freq_limits(wiphy);
return 0;
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
index 17817cdb5de2..e90a30808c22 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.h
@@ -213,6 +213,9 @@ struct vif_saved_ie {
* @list: linked list.
* @mgmt_rx_reg: registered rx mgmt frame types.
* @mbss: Multiple BSS type, set if not first AP (not relevant for P2P).
+ * @cqm_rssi_low: Lower RSSI limit for CQM monitoring
+ * @cqm_rssi_high: Upper RSSI limit for CQM monitoring
+ * @cqm_rssi_last: Last RSSI reading for CQM monitoring
*/
struct brcmf_cfg80211_vif {
struct brcmf_if *ifp;
@@ -224,6 +227,9 @@ struct brcmf_cfg80211_vif {
u16 mgmt_rx_reg;
bool mbss;
int is_11d;
+ s32 cqm_rssi_low;
+ s32 cqm_rssi_high;
+ s32 cqm_rssi_last;
};
/* association inform */
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
index 2e31cc10c195..ff2ef557f0ea 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
@@ -752,6 +752,34 @@ struct brcmf_assoclist_le {
u8 mac[BRCMF_MAX_ASSOCLIST][ETH_ALEN];
};
+/**
+ * struct brcmf_rssi_be - RSSI threshold event format
+ *
+ * @rssi: receive signal strength (in dBm)
+ * @snr: signal-noise ratio
+ * @noise: noise (in dBm)
+ */
+struct brcmf_rssi_be {
+ __be32 rssi;
+ __be32 snr;
+ __be32 noise;
+};
+
+#define BRCMF_MAX_RSSI_LEVELS 8
+
+/**
+ * struct brcm_rssi_event_le - rssi_event IOVAR format
+ *
+ * @rate_limit_msec: RSSI event rate limit
+ * @rssi_level_num: number of supplied RSSI levels
+ * @rssi_levels: RSSI levels in ascending order
+ */
+struct brcmf_rssi_event_le {
+ __le32 rate_limit_msec;
+ s8 rssi_level_num;
+ s8 rssi_levels[BRCMF_MAX_RSSI_LEVELS];
+};
+
/**
* struct brcmf_wowl_wakeind_le - Wakeup indicators
* Note: note both fields contain same information.
--
2.29.2
On Fri, 15 Jan 2021 at 15:12, Arend Van Spriel
<[email protected]> wrote:>
> + Johannes
> - netdevs
>
> On 1/14/2021 5:36 PM, 'Alvin Šipraga' via BRCM80211-DEV-LIST,PDL wrote:
> > Add support for CQM RSSI measurement reporting and advertise the
> > NL80211_EXT_FEATURE_CQM_RSSI_LIST feature. This enables a userspace
> > supplicant such as iwd to be notified of changes in the RSSI for roaming
> > and signal monitoring purposes.
>
> The more I am looking into this API the less I understand it or at least
> it raises a couple of questions. Looking into nl80211_set_cqm_rssi() [1]
> two behaviors are supported: 1) driver is provisioned with a threshold
> and hysteresis, or 2) driver is provisioned with high and low threshold.
Right.
>
> The second behavior is used when the driver advertises
> NL80211_EXT_FEATURE_CQM_RSSI_LIST *and* user-space provides more than
> one RSSI threshold.
Or, when the driver doesn't implement set_cqm_rssi_config (the old
method). So the driver can stop supporting set_cqm_rssi_config when
it implements set_cqm_rssi_range_config.
> In both cases the same driver callback is being used
> so I wonder what is expected from the driver. Seems to me the driver
> would need to be able to distinguish between the two behavioral
> scenarios. As there is no obvious way I assume the driver should behave
> the same for both cases, but again it is unclear to me what that
> expected/required behavior is.
When the driver wants to implement both methods it may be because the
hardware has a better method of handling the hysteresis than what is
implemented nl80211.c. In that case, yes, it'd need to remember which
method was used and the parameters. If set_cqm_rssi_range_config was
used the driver is expected to report when a momentary rssi
measurement goes out of the configured range.
>
> With behavior 2) some processing is done in cfg80211 itself by
> cfg80211_cqm_rssi_update() which is called from nl80211_set_cqm_rssi()
> upon NL80211_CMD_SET_CQM and cfg80211_cqm_rssi_notify() called by
> driver. If I look at that it matches pretty close what our firmware is
> doing. The difference is that our firmware avoids RSSI oscillation with
> a time constraint between RSSI events whereas cfg80211 uses the hysteresis.
That may be a good reason to keep supporting both methods.
>
> So before moving forward, I hope Johannes can chime in and clarify
> things. Added the commit message introducing the extended feature below.
> It mentions backward compatibility, but it only considers the extended
> feature setting when user-space provides more than one threshold.
Right, with one threshold the behaviour is unchanged.
> However, when the drivers set the extended feature is expects (low,
> high) and (threshold, hysteresis) if not. So it seems the extended
> feature should have precedence over the number of thresholds provided by
> user-space.
I guess the answer is that if the driver implements both methods it is
expected to report threshold crossings according to the method that
was called last.
Best regards
On 1/15/2021 3:57 PM, Alvin Šipraga wrote:
> Hi Arend,
>
> On 1/15/21 3:10 PM, Arend Van Spriel wrote:
>> + Johannes
>> - netdevs
>>
>> On 1/14/2021 5:36 PM, 'Alvin Šipraga' via BRCM80211-DEV-LIST,PDL wrote:
>>> Add support for CQM RSSI measurement reporting and advertise the
>>> NL80211_EXT_FEATURE_CQM_RSSI_LIST feature. This enables a userspace
>>> supplicant such as iwd to be notified of changes in the RSSI for roaming
>>> and signal monitoring purposes.
>>
>> The more I am looking into this API the less I understand it or at least
>> it raises a couple of questions. Looking into nl80211_set_cqm_rssi() [1]
>> two behaviors are supported: 1) driver is provisioned with a threshold
>> and hysteresis, or 2) driver is provisioned with high and low threshold. >
>> The second behavior is used when the driver advertises
>> NL80211_EXT_FEATURE_CQM_RSSI_LIST *and* user-space provides more than
>> one RSSI threshold. In both cases the same driver callback is being used
>> so I wonder what is expected from the driver. Seems to me the driver
>> would need to be able to distinguish between the two behavioral
>> scenarios. As there is no obvious way I assume the driver should behave
>> the same for both cases, but again it is unclear to me what that
>> expected/required behavior is.
>
> It will only provision the driver according to behaviour (1) if 0 or 1
> thresholds are being set AND the driver implements
> set_cqm_rssi_config(). But it says in the documentation for the
> set_cqm_rssi_range_config() callback[1] that it supersedes
> set_cqm_rssi_config() (or at least that there is no point in
> implementing _config if range_config is implemented). In that case, and
> if just one threshold is supplied (with a hysteresis), then a suitable
> range is computed by cfg80211_cqm_rssi_update() and provided to
> set_cqm_rssi_range_config(). I guess the implication here is that the
> two behaviours are functionally equivalent. I'm not sure I can argue for
> or against that because I don't really know what the semantics of the
> original API were supposed to be, but it seems reasonable.
>
> As a starting point - and since the firmware behaviour is very close
> already - I implemented only set_cqm_rssi_range(). I have been testing
> with iwd, which by default sets just a single threshold and hysteresis,
> and the driver was sending notifications as would be expected.
OK. I overlooked that there were two different callbacks involved. So I
will review the patch with that knowledge. What wifi chip did you test
this with and more importantly which firmware version?
Regards,
Arend
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Hi,
On 1/19/21 9:30 AM, Arend Van Spriel wrote:
> On 1/15/2021 3:57 PM, Alvin Šipraga wrote:
>> Hi Arend,
>>
>> On 1/15/21 3:10 PM, Arend Van Spriel wrote:
>>> + Johannes
>>> - netdevs
>>>
>>> On 1/14/2021 5:36 PM, 'Alvin Šipraga' via BRCM80211-DEV-LIST,PDL wrote:
>>>> Add support for CQM RSSI measurement reporting and advertise the
>>>> NL80211_EXT_FEATURE_CQM_RSSI_LIST feature. This enables a userspace
>>>> supplicant such as iwd to be notified of changes in the RSSI for
>>>> roaming
>>>> and signal monitoring purposes.
>>>
>>> The more I am looking into this API the less I understand it or at least
>>> it raises a couple of questions. Looking into nl80211_set_cqm_rssi() [1]
>>> two behaviors are supported: 1) driver is provisioned with a threshold
>>> and hysteresis, or 2) driver is provisioned with high and low
>>> threshold. >
>>> The second behavior is used when the driver advertises
>>> NL80211_EXT_FEATURE_CQM_RSSI_LIST *and* user-space provides more than
>>> one RSSI threshold. In both cases the same driver callback is being used
>>> so I wonder what is expected from the driver. Seems to me the driver
>>> would need to be able to distinguish between the two behavioral
>>> scenarios. As there is no obvious way I assume the driver should behave
>>> the same for both cases, but again it is unclear to me what that
>>> expected/required behavior is.
>>
>> It will only provision the driver according to behaviour (1) if 0 or 1
>> thresholds are being set AND the driver implements
>> set_cqm_rssi_config(). But it says in the documentation for the
>> set_cqm_rssi_range_config() callback[1] that it supersedes
>> set_cqm_rssi_config() (or at least that there is no point in
>> implementing _config if range_config is implemented). In that case, and
>> if just one threshold is supplied (with a hysteresis), then a suitable
>> range is computed by cfg80211_cqm_rssi_update() and provided to
>> set_cqm_rssi_range_config(). I guess the implication here is that the
>> two behaviours are functionally equivalent. I'm not sure I can argue for
>> or against that because I don't really know what the semantics of the
>> original API were supposed to be, but it seems reasonable.
>>
>> As a starting point - and since the firmware behaviour is very close
>> already - I implemented only set_cqm_rssi_range(). I have been testing
>> with iwd, which by default sets just a single threshold and hysteresis,
>> and the driver was sending notifications as would be expected.
>
> OK. I overlooked that there were two different callbacks involved. So I
> will review the patch with that knowledge. What wifi chip did you test
> this with and more importantly which firmware version?
All testing was done with a PCIe Cypress CYW88359 (Murata Type 1VA).
I tested with two firmwares:
1. A custom firmware from Cypress with some vendor-specific features:
version 9.40.98.19 (r727154 CY) FWID 01-1ff1c30
2. The latest public firmware release from Murata[1] for this chip:
version 9.40.130 (r724855 CY) FWID 01-9ae2cd6d
Thanks for the review.
[1] https://github.com/murata-wireless/cyw-fmac-fw
Kind regards,
Alvin