Patch "wifi: brcmfmac: support CQM RSSI notification with older firmware" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: brcmfmac: support CQM RSSI notification with older firmware

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-brcmfmac-support-cqm-rssi-notification-with-old.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6a746a3e439df5cf1851c039d083bfb5f42ccb3f
Author: John Keeping <john@xxxxxxxxxxxx>
Date:   Tue Jan 24 10:42:48 2023 +0000

    wifi: brcmfmac: support CQM RSSI notification with older firmware
    
    [ Upstream commit ec52d77d077529f198fd874c550a26b9cc86a331 ]
    
    Using the BCM4339 firmware from linux-firmware (version "BCM4339/2 wl0:
    Sep  5 2019 11:05:52 version 6.37.39.113 (r722271 CY)" from
    cypress/cyfmac4339-sdio.bin) the RSSI respose is only 4 bytes, which
    results in an error being logged.
    
    It seems that older devices send only the RSSI field and neither SNR nor
    noise is included.  Handle this by accepting a 4 byte message and
    reading only the RSSI from it.
    
    Fixes: 7dd56ea45a66 ("brcmfmac: add support for CQM RSSI notifications")
    Signed-off-by: John Keeping <john@xxxxxxxxxxxx>
    Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230124104248.2917465-1-john@xxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index cba909c5bc6b6..5a1b01db02e6e 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -6212,18 +6212,20 @@ static s32 brcmf_notify_rssi(struct brcmf_if *ifp,
 {
 	struct brcmf_cfg80211_vif *vif = ifp->vif;
 	struct brcmf_rssi_be *info = data;
-	s32 rssi, snr, noise;
+	s32 rssi, snr = 0, noise = 0;
 	s32 low, high, last;
 
-	if (e->datalen < sizeof(*info)) {
+	if (e->datalen >= sizeof(*info)) {
+		rssi = be32_to_cpu(info->rssi);
+		snr = be32_to_cpu(info->snr);
+		noise = be32_to_cpu(info->noise);
+	} else if (e->datalen >= sizeof(rssi)) {
+		rssi = be32_to_cpu(*(__be32 *)data);
+	} else {
 		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;