linux-kernel - [PATCH] firmware: simplify defining and handling FW_OPT

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Date:   Sun, 11 Dec 2016 14:26:26 +0100
From:   Rafał Miłecki <zajec5@...il.com>
To:     Ming Lei <ming.lei@...onical.com>,
        "Luis R . Rodriguez" <mcgrof@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc:     Rafał Miłecki <rafal@...ecki.pl>
Subject: [PATCH] firmware: simplify defining and handling FW_OPT_FALLBACK

From: Rafał Miłecki <rafal@...ecki.pl>

I found handling of FW_OPT_FALLBACK a bit complex. It was defined using
another option and their values were dependent on kernel config.

It was also non-trivial to follow the code. Some callers were using
FW_OPT_FALLBACK which was confusing since the _request_firmware function
was always checking for FW_OPT_USERHELPER (the same bit in a relevan
configuration).

With this patch FW_OPT_USERHELPER gets its own bit and is explicitly
checked in the _request_firmware which hopefully makes code easier to
understand.

Signed-off-by: Rafał Miłecki <rafal@...ecki.pl>
---
 drivers/base/firmware_class.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 22d1760..0524f8b 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -112,13 +112,9 @@ static inline long firmware_loading_timeout(void)
 #else
 #define FW_OPT_USERHELPER	0
 #endif
-#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
-#define FW_OPT_FALLBACK		FW_OPT_USERHELPER
-#else
-#define FW_OPT_FALLBACK		0
-#endif
 #define FW_OPT_NO_WARN	(1U << 3)
 #define FW_OPT_NOCACHE	(1U << 4)
+#define FW_OPT_FALLBACK	(1U << 5)
 
 struct firmware_cache {
 	/* firmware_buf instance will be added into the below list */
@@ -1175,8 +1171,12 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 			dev_warn(device,
 				 "Direct firmware load for %s failed with error %d\n",
 				 name, ret);
-		if (opt_flags & FW_OPT_USERHELPER) {
+		if (config_enabled(CONFIG_FW_LOADER_USER_HELPER_FALLBACK) &&
+		    opt_flags & FW_OPT_FALLBACK) {
 			dev_warn(device, "Falling back to user helper\n");
+			opt_flags |= FW_OPT_USERHELPER;
+		}
+		if (opt_flags & FW_OPT_USERHELPER) {
 			ret = fw_load_from_user_helper(fw, name, device,
 						       opt_flags, timeout);
 		}
-- 
2.10.1