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From: Jerome Pouiller <Jerome.Pouiller@silabs.com>
To: devel@driverdev.osuosl.org, linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Kalle Valo" <kvalo@codeaurora.org>,
	"David S . Miller" <davem@davemloft.net>,
	"Jérôme Pouiller" <jerome.pouiller@silabs.com>
Subject: [PATCH 02/31] staging: wfx: do not send CAB while scanning
Date: Fri, 10 Sep 2021 18:04:35 +0200	[thread overview]
Message-ID: <20210910160504.1794332-3-Jerome.Pouiller@silabs.com> (raw)
In-Reply-To: <20210910160504.1794332-1-Jerome.Pouiller@silabs.com>

From: Jérôme Pouiller <jerome.pouiller@silabs.com>

During the scan requests, the Tx traffic is suspended. This lock is
shared by all the network interfaces. So, a scan request on one
interface will block the traffic on a second interface. This causes
trouble when the queued traffic contains CAB (Content After DTIM Beacon)
since this traffic cannot be delayed.

It could be possible to make the lock local to each interface. But It
would only push the problem further. The device won't be able to send
the CAB before the end of the scan.

So, this patch just ignore the DTIM indication when a scan is in
progress. The firmware will send another indication on the next DTIM and
this time the system will be able to send the traffic just behind the
beacon.

The only drawback of this solution is that the stations connected to
the AP will wait for traffic after the DTIM for nothing. But since the
case is really rare it is not a big deal.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
---
 drivers/staging/wfx/sta.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index a236e5bb6914..d901588237a4 100644
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -629,8 +629,18 @@ int wfx_set_tim(struct ieee80211_hw *hw, struct ieee80211_sta *sta, bool set)
 
 void wfx_suspend_resume_mc(struct wfx_vif *wvif, enum sta_notify_cmd notify_cmd)
 {
+	struct wfx_vif *wvif_it;
+
 	if (notify_cmd != STA_NOTIFY_AWAKE)
 		return;
+
+	// Device won't be able to honor CAB if a scan is in progress on any
+	// interface. Prefer to skip this DTIM and wait for the next one.
+	wvif_it = NULL;
+	while ((wvif_it = wvif_iterate(wvif->wdev, wvif_it)) != NULL)
+		if (mutex_is_locked(&wvif_it->scan_lock))
+			return;
+
 	if (!wfx_tx_queues_has_cab(wvif) || wvif->after_dtim_tx_allowed)
 		dev_warn(wvif->wdev->dev, "incorrect sequence (%d CAB in queue)",
 			 wfx_tx_queues_has_cab(wvif));
-- 
2.33.0


  parent reply	other threads:[~2021-09-10 16:05 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-10 16:04 [PATCH 00/31] [PATCH 00/31] staging/wfx: usual maintenance Jerome Pouiller
2021-09-10 16:04 ` [PATCH 01/31] staging: wfx: use abbreviated message for "incorrect sequence" Jerome Pouiller
2021-09-10 16:04 ` Jerome Pouiller [this message]
2021-09-10 16:31   ` [PATCH 02/31] staging: wfx: do not send CAB while scanning Kari Argillander
2021-09-10 16:54     ` Jérôme Pouiller
2021-09-10 17:01       ` Kari Argillander
2021-09-10 17:12         ` Jérôme Pouiller
2021-09-10 16:04 ` [PATCH 03/31] staging: wfx: ignore PS when STA/AP share same channel Jerome Pouiller
2021-09-10 16:04 ` [PATCH 04/31] staging: wfx: wait for SCAN_CMPL after a SCAN_STOP Jerome Pouiller
2021-09-10 16:04 ` [PATCH 05/31] staging: wfx: avoid possible lock-up during scan Jerome Pouiller
2021-09-10 16:04 ` [PATCH 06/31] staging: wfx: drop unused argument from hif_scan() Jerome Pouiller
2021-09-10 16:04 ` [PATCH 07/31] staging: wfx: fix atomic accesses in wfx_tx_queue_empty() Jerome Pouiller
2021-09-10 16:04 ` [PATCH 08/31] staging: wfx: take advantage of wfx_tx_queue_empty() Jerome Pouiller
2021-09-10 16:04 ` [PATCH 09/31] staging: wfx: declare support for TDLS Jerome Pouiller
2021-09-10 16:04 ` [PATCH 10/31] staging: wfx: fix support for CSA Jerome Pouiller
2021-09-10 16:04 ` [PATCH 11/31] staging: wfx: relax the PDS existence constraint Jerome Pouiller
2021-09-10 16:04 ` [PATCH 12/31] staging: wfx: simplify API coherency check Jerome Pouiller
2021-09-10 16:04 ` [PATCH 13/31] staging: wfx: update with API 3.8 Jerome Pouiller
2021-09-10 16:43   ` Kari Argillander
2021-09-10 17:03     ` Jérôme Pouiller
2021-09-10 16:04 ` [PATCH 14/31] staging: wfx: uniformize counter names Jerome Pouiller
2021-09-10 16:04 ` [PATCH 15/31] staging: wfx: fix misleading 'rate_id' usage Jerome Pouiller
2021-09-10 16:04 ` [PATCH 16/31] staging: wfx: declare variables at beginning of functions Jerome Pouiller
2021-09-10 16:04 ` [PATCH 17/31] staging: wfx: simplify hif_join() Jerome Pouiller
2021-09-10 16:38   ` Kari Argillander
2021-09-10 16:04 ` [PATCH 18/31] staging: wfx: reorder function for slightly better eye candy Jerome Pouiller
2021-09-10 16:04 ` [PATCH 19/31] staging: wfx: fix error names Jerome Pouiller
2021-09-10 16:04 ` [PATCH 20/31] staging: wfx: apply naming rules in hif_tx_mib.c Jerome Pouiller
2021-09-10 16:04 ` [PATCH 21/31] staging: wfx: remove unused definition Jerome Pouiller
2021-09-10 16:04 ` [PATCH 22/31] staging: wfx: remove useless debug statement Jerome Pouiller
2021-09-10 16:04 ` [PATCH 23/31] staging: wfx: fix space after cast operator Jerome Pouiller
2021-09-10 16:04 ` [PATCH 24/31] staging: wfx: remove references to WFxxx in comments Jerome Pouiller
2021-09-10 16:04 ` [PATCH 25/31] staging: wfx: update files descriptions Jerome Pouiller
2021-09-10 16:04 ` [PATCH 26/31] staging: wfx: reformat comment Jerome Pouiller
2021-09-10 16:05 ` [PATCH 27/31] staging: wfx: avoid c99 comments Jerome Pouiller
2021-09-10 16:05 ` [PATCH 28/31] staging: wfx: fix comments styles Jerome Pouiller
2021-09-10 16:05 ` [PATCH 29/31] staging: wfx: remove useless comments after #endif Jerome Pouiller
2021-09-10 16:27   ` Kari Argillander
2021-09-10 16:49     ` Jérôme Pouiller
2021-09-10 17:05       ` Kari Argillander
2021-09-10 16:05 ` [PATCH 30/31] staging: wfx: explain the purpose of wfx_send_pds() Jerome Pouiller
2021-09-10 16:05 ` [PATCH 31/31] staging: wfx: indent functions arguments Jerome Pouiller
2021-09-10 16:57   ` Kari Argillander
2021-09-10 17:12     ` Jérôme Pouiller
2021-09-10 17:28       ` Kari Argillander
2021-09-10 17:07 ` [PATCH 00/31] [PATCH 00/31] staging/wfx: usual maintenance Kari Argillander
2021-09-10 17:15   ` Jérôme Pouiller

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