firmware_class: make firmware caching configurable

Because firmware caching generates uevent messages that are sent over
a netlink socket, it can prevent suspend on many platforms.  It's
also not always useful, so make it a configurable option.
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20191113225429.118495-1-salyzyn@android.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_loader/Kconfig

@@ -169,5 +169,17 @@ config FW_LOADER_COMPRESS
 	  be compressed with either none or crc32 integrity check type (pass
 	  "-C crc32" option to xz command).
 
+config FW_CACHE
+	bool "Enable firmware caching during suspend"
+	depends on PM_SLEEP
+	default y if PM_SLEEP
+	help
+	  Because firmware caching generates uevent messages that are sent
+	  over a netlink socket, it can prevent suspend on many platforms.
+	  It is also not always useful, so on such platforms we have the
+	  option.
+
+	  If unsure, say Y.
+
 endif # FW_LOADER
 endmenu

drivers/base/firmware_loader/main.c

@@ -51,7 +51,7 @@ struct firmware_cache {
 	struct list_head head;
 	int state;
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_FW_CACHE
 	/*
 	 * Names of firmware images which have been cached successfully
 	 * will be added into the below list so that device uncache
@@ -557,7 +557,7 @@ static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 		 (unsigned int)fw_priv->size);
 }
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_FW_CACHE
 static void fw_name_devm_release(struct device *dev, void *res)
 {
 	struct fw_name_devm *fwn = res;
@@ -1047,7 +1047,7 @@ request_firmware_nowait(
 }
 EXPORT_SYMBOL(request_firmware_nowait);
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_FW_CACHE
 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
 
 /**