linux-kernel - [PATCH 1/5] firmware: share fw fallback killing on reboot/suspend

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Date:   Wed, 29 Mar 2017 20:24:46 -0700
From:   "Luis R. Rodriguez" <mcgrof@...nel.org>
To:     gregkh@...uxfoundation.org
Cc:     wagi@...om.org, dwmw2@...radead.org, rafal@...ecki.pl,
        arend.vanspriel@...adcom.com, rjw@...ysocki.net,
        yi1.li@...ux.intel.com, atull@...nsource.altera.com,
        moritz.fischer@...us.com, pmladek@...e.com,
        johannes.berg@...el.com, emmanuel.grumbach@...el.com,
        luciano.coelho@...el.com, kvalo@...eaurora.org, luto@...nel.org,
        takahiro.akashi@...aro.org, dhowells@...hat.com, pjones@...hat.com,
        linux-kernel@...r.kernel.org,
        "Luis R. Rodriguez" <mcgrof@...nel.org>
Subject: [PATCH 1/5] firmware: share fw fallback killing on reboot/suspend

We kill pending fallback requests on suspend and reboot,
the only difference is that on suspend we only kill custom
fallback requests. Provide a wrapper that lets us customize
the request with a flag.

This also lets us simplify the #ifdef'ery over the calls.

Signed-off-by: Luis R. Rodriguez <mcgrof@...nel.org>
---
 drivers/base/firmware_class.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index ac350c518e0c..d2e2d83aaf26 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -562,16 +562,15 @@ static void fw_load_abort(struct firmware_priv *fw_priv)
 
 static LIST_HEAD(pending_fw_head);
 
-/* reboot notifier for avoid deadlock with usermode_lock */
 static int fw_shutdown_notify(struct notifier_block *unused1,
 			      unsigned long unused2, void *unused3)
 {
-	mutex_lock(&fw_lock);
-	while (!list_empty(&pending_fw_head))
-		__fw_load_abort(list_first_entry(&pending_fw_head,
-					       struct firmware_buf,
-					       pending_list));
-	mutex_unlock(&fw_lock);
+	/*
+	 * Kill all pending fallback requests to avoid both stalling shutdown,
+	 * and avoid a deadlock with the usermode_lock.
+	 */
+	kill_pending_fw_fallback_reqs(false);
+
 	return NOTIFY_DONE;
 }
 
@@ -1048,21 +1047,20 @@ static int fw_load_from_user_helper(struct firmware *firmware,
 	return _request_firmware_load(fw_priv, opt_flags, timeout);
 }
 
-#ifdef CONFIG_PM_SLEEP
-/* kill pending requests without uevent to avoid blocking suspend */
-static void kill_requests_without_uevent(void)
+static void kill_pending_fw_fallback_reqs(bool only_kill_custom)
 {
 	struct firmware_buf *buf;
 	struct firmware_buf *next;
 
 	mutex_lock(&fw_lock);
 	list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
-		if (!buf->need_uevent)
+		if (!only_kill_custom)
+			 __fw_load_abort(buf);
+		else if (!buf->need_uevent)
 			 __fw_load_abort(buf);
 	}
 	mutex_unlock(&fw_lock);
 }
-#endif
 
 #else /* CONFIG_FW_LOADER_USER_HELPER */
 static inline int
@@ -1073,9 +1071,7 @@ fw_load_from_user_helper(struct firmware *firmware, const char *name,
 	return -ENOENT;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static inline void kill_requests_without_uevent(void) { }
-#endif
+static inline void kill_pending_fw_fallback_reqs(bool only_kill_custom) { }
 
 #endif /* CONFIG_FW_LOADER_USER_HELPER */
 
@@ -1724,7 +1720,11 @@ static int fw_pm_notify(struct notifier_block *notify_block,
 	case PM_HIBERNATION_PREPARE:
 	case PM_SUSPEND_PREPARE:
 	case PM_RESTORE_PREPARE:
-		kill_requests_without_uevent();
+		/*
+		 * kill pending fallback requests with a custom fallback
+		 * to avoid stalling suspend.
+		 */
+		kill_pending_fw_fallback_reqs(true);
 		device_cache_fw_images();
 		break;
 
-- 
2.11.0