Re: [PATCH] firmware loader: inform direct failure when udev loader is disabled

[Luis R. Rodriguez]

On Tue, Jul 01, 2014 at 11:22:07AM +0200, Takashi Iwai wrote:
> At Tue, 1 Jul 2014 11:54:24 +0800,
> Ming Lei wrote:
> > 
> > On Tue, Jul 1, 2014 at 7:30 AM, Luis R. Rodriguez
> > <mcgrof@xxxxxxxxxxxxxxxx> wrote:
> > > From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx>
> > >
> > > 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@xxxxxxx>
> > > Cc: Ming Lei <ming.lei@xxxxxxxxxxxxx>
> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > Cc: Abhay Salunke <Abhay_Salunke@xxxxxxxx>
> > > Cc: Stefan Roese <sr@xxxxxxx>
> > > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > > Cc: Kay Sievers <kay@xxxxxxxx>
> > > Cc: Takashi Iwai <tiwai@xxxxxxx>
> > > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx>
> > > ---
> > >
> > >  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);
> > 
> > Maybe the warning can be always printed out since
> > (FW_OPT_FAIL_WARN | FW_OPT_USERHELPER) should be
> > always true.
> 
> Yes, it'd be simpler.  Let's reduce lines! :)

Actually we don't want to warn when request_firmware_direct() is used right? That's really what
I meant to upkeep while adding a warning when _direct() is not used. So how about
this as an ammendment:

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 23274d8..4f6adf3 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1180,7 +1180,6 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 }
 EXPORT_SYMBOL(request_firmware);
 
-#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 /**
  * request_firmware: - load firmware directly without usermode helper
  * @firmware_p: pointer to firmware image
@@ -1202,7 +1201,6 @@ int request_firmware_direct(const struct firmware **firmware_p,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(request_firmware_direct);
-#endif
 
 /**
  * release_firmware: - release the resource associated with a firmware image
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index 67e5b80..5c41c5e 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -45,6 +45,8 @@ int request_firmware_nowait(
 	struct module *module, bool uevent,
 	const char *name, struct device *device, gfp_t gfp, void *context,
 	void (*cont)(const struct firmware *fw, void *context));
+int request_firmware_direct(const struct firmware **fw, const char *name,
+			    struct device *device);
 
 void release_firmware(const struct firmware *fw);
 #else
@@ -66,13 +68,12 @@ static inline void release_firmware(const struct firmware *fw)
 {
 }
 
-#endif
+static inline int request_firmware_direct(const struct firmware **fw,
+					  const char *name,
+					  struct device *device)
+{
+	return -EINVAL;
+}
 
-#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
-int request_firmware_direct(const struct firmware **fw, const char *name,
-			    struct device *device);
-#else
-#define request_firmware_direct	request_firmware
 #endif
-
 #endif
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/