wil6210: prevent parallel suspend and dump collection

Suspend and crash dump operations can happen simultaneously
in case there is a FW assert during the suspend procedure
or when SSR calls all the devices crashdump callbacks.

To prevent that, a new flag is added, indicating that the
dumps collection is in progress, in order to allow the
suspend/reset decline if the dumps collection already started.
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/wil6210/main.c

@@ -998,6 +998,7 @@ static void wil_pre_fw_config(struct wil6210_priv *wil)
 int wil_reset(struct wil6210_priv *wil, bool load_fw)
 {
 	int rc;
+	unsigned long status_flags = BIT(wil_status_resetting);
 
 	wil_dbg_misc(wil, "reset\n");
 
@@ -1037,6 +1038,14 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 	}
 
 	set_bit(wil_status_resetting, wil->status);
+	if (test_bit(wil_status_collecting_dumps, wil->status)) {
+		/* Device collects crash dump, cancel the reset.
+		 * following crash dump collection, reset would take place.
+		 */
+		wil_dbg_misc(wil, "reject reset while collecting crash dump\n");
+		rc = -EBUSY;
+		goto out;
+	}
 
 	cancel_work_sync(&wil->disconnect_worker);
 	wil6210_disconnect(wil, NULL, WLAN_REASON_DEAUTH_LEAVING, false);
@@ -1051,7 +1060,11 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 
 	/* prevent NAPI from being scheduled and prevent wmi commands */
 	mutex_lock(&wil->wmi_mutex);
-	bitmap_zero(wil->status, wil_status_last);
+	if (test_bit(wil_status_suspending, wil->status))
+		status_flags |= BIT(wil_status_suspending);
+	bitmap_and(wil->status, wil->status, &status_flags,
+		   wil_status_last);
+	wil_dbg_misc(wil, "wil->status (0x%lx)\n", *wil->status);
 	mutex_unlock(&wil->wmi_mutex);
 
 	wil_mask_irq(wil);
@@ -1069,14 +1082,14 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 	wil_rx_fini(wil);
 	if (rc) {
 		wil_bl_crash_info(wil, true);
-		return rc;
+		goto out;
 	}
 
 	rc = wil_get_bl_info(wil);
 	if (rc == -EAGAIN && !load_fw) /* ignore RF error if not going up */
 		rc = 0;
 	if (rc)
-		return rc;
+		goto out;
 
 	wil_set_oob_mode(wil, oob_mode);
 	if (load_fw) {
@@ -1088,10 +1101,10 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 		/* Loading f/w from the file */
 		rc = wil_request_firmware(wil, wil->wil_fw_name, true);
 		if (rc)
-			return rc;
+			goto out;
 		rc = wil_request_firmware(wil, WIL_BOARD_FILE_NAME, true);
 		if (rc)
-			return rc;
+			goto out;
 
 		wil_pre_fw_config(wil);
 		wil_release_cpu(wil);
@@ -1103,6 +1116,8 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 	reinit_completion(&wil->wmi_call);
 	reinit_completion(&wil->halp.comp);
 
+	clear_bit(wil_status_resetting, wil->status);
+
 	if (load_fw) {
 		wil_configure_interrupt_moderation(wil);
 		wil_unmask_irq(wil);
@@ -1136,6 +1151,10 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 	}
 
 	return rc;
+
+out:
+	clear_bit(wil_status_resetting, wil->status);
+	return rc;
 }
 
 void wil_fw_error_recovery(struct wil6210_priv *wil)
@@ -1241,9 +1260,7 @@ int __wil_down(struct wil6210_priv *wil)
 	wil_abort_scan(wil, false);
 	mutex_unlock(&wil->p2p_wdev_mutex);
 
-	wil_reset(wil, false);
-
-	return 0;
+	return wil_reset(wil, false);
 }
 
 int wil_down(struct wil6210_priv *wil)

drivers/net/wireless/ath/wil6210/pm.c

@@ -145,6 +145,13 @@ static int wil_suspend_keep_radio_on(struct wil6210_priv *wil)
 
 	/* Prevent handling of new tx and wmi commands */
 	set_bit(wil_status_suspending, wil->status);
+	if (test_bit(wil_status_collecting_dumps, wil->status)) {
+		/* Device collects crash dump, cancel the suspend */
+		wil_dbg_pm(wil, "reject suspend while collecting crash dump\n");
+		clear_bit(wil_status_suspending, wil->status);
+		wil->suspend_stats.rejected_by_host++;
+		return -EBUSY;
+	}
 	wil_update_net_queues_bh(wil, NULL, true);
 
 	if (!wil_is_tx_idle(wil)) {
@@ -255,6 +262,15 @@ static int wil_suspend_radio_off(struct wil6210_priv *wil)
 
 	wil_dbg_pm(wil, "suspend radio off\n");
 
+	set_bit(wil_status_suspending, wil->status);
+	if (test_bit(wil_status_collecting_dumps, wil->status)) {
+		/* Device collects crash dump, cancel the suspend */
+		wil_dbg_pm(wil, "reject suspend while collecting crash dump\n");
+		clear_bit(wil_status_suspending, wil->status);
+		wil->suspend_stats.rejected_by_host++;
+		return -EBUSY;
+	}
+
 	/* if netif up, hardware is alive, shut it down */
 	if (ndev->flags & IFF_UP) {
 		rc = wil_down(wil);
@@ -281,6 +297,7 @@ static int wil_suspend_radio_off(struct wil6210_priv *wil)
 	set_bit(wil_status_suspended, wil->status);
 
 out:
+	clear_bit(wil_status_suspending, wil->status);
 	wil_dbg_pm(wil, "suspend radio off: %d\n", rc);
 
 	return rc;

drivers/net/wireless/ath/wil6210/wil6210.h

@@ -445,6 +445,7 @@ enum { /* for wil6210_priv.status */
 	wil_status_suspending, /* suspend in progress */
 	wil_status_suspended, /* suspend completed, device is suspended */
 	wil_status_resuming, /* resume in progress */
+	wil_status_collecting_dumps, /* crashdump collection in progress */
 	wil_status_last /* keep last */
 };
 

drivers/net/wireless/ath/wil6210/wil_crash_dump.c

@@ -72,6 +72,15 @@ int wil_fw_copy_crash_dump(struct wil6210_priv *wil, void *dest, u32 size)
 		return -EINVAL;
 	}
 
+	set_bit(wil_status_collecting_dumps, wil->status);
+	if (test_bit(wil_status_suspending, wil->status) ||
+	    test_bit(wil_status_suspended, wil->status) ||
+	    test_bit(wil_status_resetting, wil->status)) {
+		wil_err(wil, "cannot collect fw dump during suspend/reset\n");
+		clear_bit(wil_status_collecting_dumps, wil->status);
+		return -EINVAL;
+	}
+
 	/* copy to crash dump area */
 	for (i = 0; i < ARRAY_SIZE(fw_mapping); i++) {
 		map = &fw_mapping[i];
@@ -91,6 +100,8 @@ int wil_fw_copy_crash_dump(struct wil6210_priv *wil, void *dest, u32 size)
 				     (const void __iomem * __force)data, len);
 	}
 
+	clear_bit(wil_status_collecting_dumps, wil->status);
+
 	return 0;
 }