From 5a1379e8748a5cfa3eb068f812d61bde849ef76c Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 4 Jun 2014 17:48:15 +0200 Subject: [PATCH] firmware loader: allow disabling of udev as firmware loader [The patch was originally proposed by Tom Gundersen, and rewritten afterwards by me; most of changelogs below borrowed from Tom's original patch -- tiwai] Currently (at least) the dell-rbu driver selects FW_LOADER_USER_HELPER, which means that distros can't really stop loading firmware through udev without breaking other users (though some have). Ideally we would remove/disable the udev firmware helper in both the kernel and in udev, but if we were to disable it in udev and not the kernel, the result would be (seemingly) hung kernels as no one would be around to cancel firmware requests. This patch allows udev firmware loading to be disabled while still allowing non-udev firmware loading, as done by the dell-rbu driver, to continue working. This is achieved by only using the fallback mechanism when the uevent is suppressed. The patch renames the user-selectable Kconfig from FW_LOADER_USER_HELPER to FW_LOADER_USER_HELPER_FALLBACK, and the former is reverse-selected by the latter or the drivers that need userhelper like dell-rbu. Also, the "default y" is removed together with this change, since it's been deprecated in udev upstream, thus rather better to disable it nowadays. Tested with FW_LOADER_USER_HELPER=n LATTICE_ECP3_CONFIG=y DELL_RBU=y and udev without the firmware loading support, but I don't have the hardware to test the lattice/dell drivers, so additional testing would be appreciated. Reviewed-by: Tom Gundersen Cc: Ming Lei Cc: Abhay Salunke Cc: Stefan Roese Cc: Arnd Bergmann Cc: Kay Sievers Tested-by: Balaji Singh Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- drivers/base/Kconfig | 10 ++++++++-- drivers/base/firmware_class.c | 15 ++++++++++----- include/linux/firmware.h | 2 +- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 00e13ce5cbbd..88500fed3c7a 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -149,15 +149,21 @@ config EXTRA_FIRMWARE_DIR some other directory containing the firmware files. config FW_LOADER_USER_HELPER + bool + +config FW_LOADER_USER_HELPER_FALLBACK bool "Fallback user-helper invocation for firmware loading" depends on FW_LOADER - default y + select FW_LOADER_USER_HELPER help This option enables / disables the invocation of user-helper (e.g. udev) for loading firmware files as a fallback after the direct file loading in kernel fails. The user-mode helper is no longer required unless you have a special firmware file that - resides in a non-standard path. + resides in a non-standard path. Moreover, the udev support has + been deprecated upstream. + + If you are unsure about this, say N here. config DEBUG_DRIVER bool "Driver Core verbose debug messages" diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index d276e33880be..46ea5f4c3bb5 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -100,9 +100,14 @@ static inline long firmware_loading_timeout(void) #define FW_OPT_UEVENT (1U << 0) #define FW_OPT_NOWAIT (1U << 1) #ifdef CONFIG_FW_LOADER_USER_HELPER -#define FW_OPT_FALLBACK (1U << 2) +#define FW_OPT_USERHELPER (1U << 2) #else -#define FW_OPT_FALLBACK 0 +#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 struct firmware_cache { @@ -1111,7 +1116,7 @@ _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_FALLBACK) { + if (opt_flags & FW_OPT_USERHELPER) { dev_warn(device, "Direct firmware load failed with error %d\n", ret); @@ -1171,7 +1176,7 @@ request_firmware(const struct firmware **firmware_p, const char *name, } EXPORT_SYMBOL(request_firmware); -#ifdef CONFIG_FW_LOADER_USER_HELPER +#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK /** * request_firmware: - load firmware directly without usermode helper * @firmware_p: pointer to firmware image @@ -1277,7 +1282,7 @@ request_firmware_nowait( fw_work->context = context; fw_work->cont = cont; fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK | - (uevent ? FW_OPT_UEVENT : 0); + (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER); if (!try_module_get(module)) { kfree(fw_work); diff --git a/include/linux/firmware.h b/include/linux/firmware.h index 59529330efd6..67e5b801af0c 100644 --- a/include/linux/firmware.h +++ b/include/linux/firmware.h @@ -68,7 +68,7 @@ static inline void release_firmware(const struct firmware *fw) #endif -#ifdef CONFIG_FW_LOADER_USER_HELPER +#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK int request_firmware_direct(const struct firmware **fw, const char *name, struct device *device); #else -- GitLab