When CONFIG_FW_LOADER_USER_HELPER is set, request_firmware() falls
back to the usermode helper for loading via udev when the direct
loading fails. But the recent udev takes way too long timeout (60
seconds) for non-existing firmware. This is unacceptable for the
drivers like microcode loader where they load firmwares optionally,
i.e. it's no error even if no requested file exists.
This patch provides a new helper function, request_firmware_direct().
It behaves as same as request_firmware() except for that it doesn't
fall back to usermode helper but returns an error immediately if the
f/w can't be loaded directly in kernel.
Without CONFIG_FW_LOADER_USER_HELPER=y, request_firmware_direct() is
just an alias of request_firmware(), due to obvious reason.
Tested-by: Prarit Bhargava <pra...@redhat.com>
Acked-by: Ming Lei <ming....@canonical.com>
Acked-by: Borislav Petkov <b...@suse.de>
Signed-off-by: Takashi Iwai <ti...@suse.de>
---
drivers/base/firmware_class.c | 41 ++++++++++++++++++++++++++++++++++-------
include/linux/firmware.h | 7 +++++++
2 files changed, 41 insertions(+), 7 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index eb8fb94ae2c5..1af03648daf8 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1061,7 +1061,7 @@ static int assign_firmware_buf(struct firmware *fw,
struct device *device,
/* called from request_firmware() and request_firmware_work_func() */
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
- struct device *device, bool uevent, bool nowait)
+ struct device *device, bool uevent, bool nowait, bool
fallback)
{
struct firmware *fw;
long timeout;
@@ -1095,11 +1095,14 @@ _request_firmware(const struct firmware **firmware_p,
const char *name,
ret = fw_get_filesystem_firmware(device, fw->priv);
if (ret) {
- dev_warn(device, "Direct firmware load failed with error %d\n",
- ret);
- dev_warn(device, "Falling back to user helper\n");
- ret = fw_load_from_user_helper(fw, name, device,
+ if (fallback) {
+ dev_warn(device,
+ "Direct firmware load failed with error %d\n",
+ ret);
+ dev_warn(device, "Falling back to user helper\n");
+ ret = fw_load_from_user_helper(fw, name, device,
uevent, nowait, timeout);
+ }
}
/* don't cache firmware handled without uevent */
@@ -1146,12 +1149,36 @@ 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, true, false);
+ ret = _request_firmware(firmware_p, name, device, true, false, true);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware);
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+/**
+ * request_firmware: - load firmware directly without usermode helper
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ * This function works pretty much like request_firmware(), but this doesn't
+ * fall back to usermode helper even if the firmware couldn't be loaded
+ * directly from fs. Hence it's useful for loading optional firmwares, which
+ * aren't always present, without extra long timeouts of udev.
+ **/
+int request_firmware_direct(const struct firmware **firmware_p,
+ const char *name, struct device *device)
+{
+ int ret;
+ __module_get(THIS_MODULE);
+ ret = _request_firmware(firmware_p, name, device, true, false, false);
+ module_put(THIS_MODULE);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(request_firmware_direct);
+#endif
+
/**
* release_firmware: - release the resource associated with a firmware image
* @fw: firmware resource to release
@@ -1185,7 +1212,7 @@ static void request_firmware_work_func(struct work_struct
*work)
fw_work = container_of(work, struct firmware_work, work);
_request_firmware(&fw, fw_work->name, fw_work->device,
- fw_work->uevent, true);
+ fw_work->uevent, true, true);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index e154c1005cd1..59529330efd6 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -68,4 +68,11 @@ static inline void release_firmware(const struct firmware
*fw)
#endif
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+int request_firmware_direct(const struct firmware **fw, const char *name,
+ struct device *device);
+#else
+#define request_firmware_direct request_firmware
+#endif
+
#endif
--
1.8.4.2
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