linux-kernel - [PATCH] firmware loader: inform direct failure when udev loader is disabled

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Date:	Mon, 30 Jun 2014 16:30:17 -0700
From:	"Luis R. Rodriguez" <mcgrof@...not-panic.com>
To:	ming.lei@...onical.com, gregkh@...uxfoundation.org
Cc:	linux-kernel@...r.kernel.org,
	"Luis R. Rodriguez" <mcgrof@...e.com>, Tom Gundersen <teg@...m.no>,
	Abhay Salunke <Abhay_Salunke@...l.com>,
	Stefan Roese <sr@...x.de>, Arnd Bergmann <arnd@...db.de>,
	Kay Sievers <kay@...y.org>, Takashi Iwai <tiwai@...e.de>
Subject: [PATCH] firmware loader: inform direct failure when udev loader is disabled

From: "Luis R. Rodriguez" <mcgrof@...e.com>

Now that the udev firmware loader is optional request_firmware()
will not provide any information on the kernel ring buffer if
direct firmware loading failed and udev firmware loading is disabled.
If no information is needed request_firmware_direct() should be used
for optional firmware, at which point drivers can take on the onus
over informing of any failures, if udev firmware loading is disabled
though we should at the very least provide some sort of information
as when the udev loader was enabled by default back in the days.

With this change with a simple firmware load test module [0]:

Example output without FW_LOADER_USER_HELPER_FALLBACK

platform fake-dev.0: Direct firmware load for fake.bin failed with error -2

Example without FW_LOADER_USER_HELPER_FALLBACK

platform fake-dev.0: Direct firmware load for fake.bin failed with error -2     
platform fake-dev.0: Falling back to user helper 

Without this change without FW_LOADER_USER_HELPER_FALLBACK we get no output
logged upon failure.

[0] https://github.com/mcgrof/fake-firmware-test.git

Cc: Tom Gundersen <teg@...m.no>
Cc: Ming Lei <ming.lei@...onical.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Abhay Salunke <Abhay_Salunke@...l.com>
Cc: Stefan Roese <sr@...x.de>
Cc: Arnd Bergmann <arnd@...db.de>
Cc: Kay Sievers <kay@...y.org>
Cc: Takashi Iwai <tiwai@...e.de>
Signed-off-by: Luis R. Rodriguez <mcgrof@...e.com>
---

 drivers/base/firmware_class.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 46ea5f4..23274d8 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -101,8 +101,10 @@ static inline long firmware_loading_timeout(void)
 #define FW_OPT_NOWAIT	(1U << 1)
 #ifdef CONFIG_FW_LOADER_USER_HELPER
 #define FW_OPT_USERHELPER	(1U << 2)
+#define FW_OPT_FAIL_WARN	0
 #else
 #define FW_OPT_USERHELPER	0
+#define FW_OPT_FAIL_WARN	(1U << 3)
 #endif
 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 #define FW_OPT_FALLBACK		FW_OPT_USERHELPER
@@ -1116,10 +1118,11 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 
 	ret = fw_get_filesystem_firmware(device, fw->priv);
 	if (ret) {
-		if (opt_flags & FW_OPT_USERHELPER) {
+		if (opt_flags & (FW_OPT_FAIL_WARN | FW_OPT_USERHELPER))
 			dev_warn(device,
-				 "Direct firmware load failed with error %d\n",
-				 ret);
+				 "Direct firmware load for %s failed with error %d\n",
+				 name, ret);
+		if (opt_flags & FW_OPT_USERHELPER) {
 			dev_warn(device, "Falling back to user helper\n");
 			ret = fw_load_from_user_helper(fw, name, device,
 						       opt_flags, timeout);
@@ -1170,7 +1173,8 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 	/* Need to pin this module until return */
 	__module_get(THIS_MODULE);
 	ret = _request_firmware(firmware_p, name, device,
-				FW_OPT_UEVENT | FW_OPT_FALLBACK);
+				FW_OPT_UEVENT | FW_OPT_FALLBACK |
+				FW_OPT_FAIL_WARN);
 	module_put(THIS_MODULE);
 	return ret;
 }
-- 
2.0.0

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