brcmfmac: screening firmware event packet

Firmware uses asynchronized events as a communication method to the
host. The event packets are marked as ETH_P_LINK_CTL protocol type. For
SDIO and PCIe bus, this kind of packets are delivered through virtual
event channel not data channel. This patch adds a screening logic to
make sure the event handler only processes the events coming from the
correct channel.

Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Signed-off-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 48d7467..4252fa8 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -1294,6 +1294,17 @@
 	return (u8)((hdrvalue & SDPCM_DOFFSET_MASK) >> SDPCM_DOFFSET_SHIFT);
 }
 
+static inline bool brcmf_sdio_fromevntchan(u8 *swheader)
+{
+	u32 hdrvalue;
+	u8 ret;
+
+	hdrvalue = *(u32 *)swheader;
+	ret = (u8)((hdrvalue & SDPCM_CHANNEL_MASK) >> SDPCM_CHANNEL_SHIFT);
+
+	return (ret == SDPCM_EVENT_CHANNEL);
+}
+
 static int brcmf_sdio_hdparse(struct brcmf_sdio *bus, u8 *header,
 			      struct brcmf_sdio_hdrinfo *rd,
 			      enum brcmf_sdio_frmtype type)
@@ -1641,7 +1652,11 @@
 					   pfirst->len, pfirst->next,
 					   pfirst->prev);
 			skb_unlink(pfirst, &bus->glom);
-			brcmf_rx_frame(bus->sdiodev->dev, pfirst);
+			if (brcmf_sdio_fromevntchan(pfirst->data))
+				brcmf_rx_event(bus->sdiodev->dev, pfirst);
+			else
+				brcmf_rx_frame(bus->sdiodev->dev, pfirst,
+					       false);
 			bus->sdcnt.rxglompkts++;
 		}
 
@@ -1967,18 +1982,19 @@
 		__skb_trim(pkt, rd->len);
 		skb_pull(pkt, rd->dat_offset);
 
+		if (pkt->len == 0)
+			brcmu_pkt_buf_free_skb(pkt);
+		else if (rd->channel == SDPCM_EVENT_CHANNEL)
+			brcmf_rx_event(bus->sdiodev->dev, pkt);
+		else
+			brcmf_rx_frame(bus->sdiodev->dev, pkt,
+				       false);
+
 		/* prepare the descriptor for the next read */
 		rd->len = rd->len_nxtfrm << 4;
 		rd->len_nxtfrm = 0;
 		/* treat all packet as event if we don't know */
 		rd->channel = SDPCM_EVENT_CHANNEL;
-
-		if (pkt->len == 0) {
-			brcmu_pkt_buf_free_skb(pkt);
-			continue;
-		}
-
-		brcmf_rx_frame(bus->sdiodev->dev, pkt);
 	}
 
 	rxcount = maxframes - rxleft;