Patch "wifi: ath10k: poll service ready message before failing" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    wifi: ath10k: poll service ready message before failing

to the 5.4-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-ath10k-poll-service-ready-message-before-failin.patch
and it can be found in the queue-5.4 subdirectory.

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



commit a041e3bf4d03cbe2ac820bd891e22ab8af49222f
Author: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
Date:   Wed Mar 6 07:15:14 2024 +0200

    wifi: ath10k: poll service ready message before failing
    
    [ Upstream commit e57b7d62a1b2f496caf0beba81cec3c90fad80d5 ]
    
    Currently host relies on CE interrupts to get notified that
    the service ready message is ready. This results in timeout
    issue if the interrupt is not fired, due to some unknown
    reasons. See below logs:
    
    [76321.937866] ath10k_pci 0000:02:00.0: wmi service ready event not received
    ...
    [76322.016738] ath10k_pci 0000:02:00.0: Could not init core: -110
    
    And finally it causes WLAN interface bring up failure.
    
    Change to give it one more chance here by polling CE rings,
    before failing directly.
    
    Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00157-QCARMSWPZ-1
    
    Fixes: 5e3dd157d7e7 ("ath10k: mac80211 driver for Qualcomm Atheros 802.11ac CQA98xx devices")
    Reported-by: James Prestwood <prestwoj@xxxxxxxxx>
    Tested-By: James Prestwood <prestwoj@xxxxxxxxx> # on QCA6174 hw3.2
    Link: https://lore.kernel.org/linux-wireless/304ce305-fbe6-420e-ac2a-d61ae5e6ca1a@xxxxxxxxx/
    Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
    Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
    Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
    Link: https://msgid.link/20240227030409.89702-1-quic_bqiang@xxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 4adbe3ab9c870..81689dbab7f49 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -1720,12 +1720,32 @@ void ath10k_wmi_put_wmi_channel(struct wmi_channel *ch,
 
 int ath10k_wmi_wait_for_service_ready(struct ath10k *ar)
 {
-	unsigned long time_left;
+	unsigned long time_left, i;
 
 	time_left = wait_for_completion_timeout(&ar->wmi.service_ready,
 						WMI_SERVICE_READY_TIMEOUT_HZ);
-	if (!time_left)
-		return -ETIMEDOUT;
+	if (!time_left) {
+		/* Sometimes the PCI HIF doesn't receive interrupt
+		 * for the service ready message even if the buffer
+		 * was completed. PCIe sniffer shows that it's
+		 * because the corresponding CE ring doesn't fires
+		 * it. Workaround here by polling CE rings once.
+		 */
+		ath10k_warn(ar, "failed to receive service ready completion, polling..\n");
+
+		for (i = 0; i < CE_COUNT; i++)
+			ath10k_hif_send_complete_check(ar, i, 1);
+
+		time_left = wait_for_completion_timeout(&ar->wmi.service_ready,
+							WMI_SERVICE_READY_TIMEOUT_HZ);
+		if (!time_left) {
+			ath10k_warn(ar, "polling timed out\n");
+			return -ETIMEDOUT;
+		}
+
+		ath10k_warn(ar, "service ready completion received, continuing normally\n");
+	}
+
 	return 0;
 }