From 3d25753554e7b4dedfc561edb03e635f97854fa6 Mon Sep 17 00:00:00 2001 From: Vitaliy Sochnev Date: Fri, 7 Aug 2026 11:09:49 +0100 Subject: [PATCH] airoha: npu: load the firmware without the sysfs fallback The NPU driver maps a missing firmware file to -EPROBE_DEFER, so that it can be retried once the rootfs carrying /lib/firmware is mounted. That mapping holds only while request_firmware() reports -ENOENT, and it does not when the sysfs fallback is in play: the request goes to a userspace helper, blocks for the full 60 second loading_timeout and comes back as -ETIMEDOUT, which dev_err_probe() then turns into a hard failure. The board boots a minute slower and ends up with no NPU at all, so no hardware flow offloading either. Our own config disables FW_LOADER_USER_HELPER for the target, but that is not a dependable guard: LEDS_LP55XX_COMMON selects it, so any build that pulls in kmod-leds-lp55xx-common - every image built with ALL_KMODS, snapshots included - gets it back, and generic's FW_LOADER_USER_HELPER_FALLBACK=y then arms the fallback. Add a patch switching the driver to request_firmware_direct(), which sets FW_OPT_NOFALLBACK_SYSFS and so reports -ENOENT whatever the firmware loader is configured to do. request_firmware_direct() also sets FW_OPT_NO_WARN, so the "Direct firmware load for airoha/en7581_npu_rv32.bin failed with error -2" line goes away together with the fallback. There is no variant that skips the fallback but keeps the warning. While the probe is being deferred that message was noise, but on a board where the firmware package is genuinely missing it was the only hint naming the file. Measured on a Nokia XG-040G-MD with FW_LOADER_USER_HELPER=y and FW_LOADER_USER_HELPER_FALLBACK=y forced on, the two images differing only by this patch: without: 2.477 fallback -> 64.555 -ETIMEDOUT -> probe failed -110, preinit at 69.6s, NPU unbound with: no fallback and no warning at all, NPU fw version 1456.62 at 3.665s, preinit at 7.6s Note the fallback is still compiled in and forced in both cases; the patch does not disable it, it only keeps the driver from falling into it. The patch carries Fixes: 23290c7bc190 ("net: airoha: Introduce Airoha NPU support") and Cc: stable@vger.kernel.org, so it can be dropped once it lands upstream and reaches us through a stable update. Link: https://lore.kernel.org/netdev/20260807024125.434055-1-sochnev.v.74@gmail.com/ Signed-off-by: Vitaliy Sochnev Link: https://github.com/openwrt/openwrt/pull/24593 Signed-off-by: Robert Marko --- ...oad-firmware-without-the-sysfs-fallb.patch | 59 +++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 target/linux/airoha/patches-6.18/921-net-airoha-npu-load-firmware-without-the-sysfs-fallb.patch diff --git a/target/linux/airoha/patches-6.18/921-net-airoha-npu-load-firmware-without-the-sysfs-fallb.patch b/target/linux/airoha/patches-6.18/921-net-airoha-npu-load-firmware-without-the-sysfs-fallb.patch new file mode 100644 index 00000000000..a07845abbf9 --- /dev/null +++ b/target/linux/airoha/patches-6.18/921-net-airoha-npu-load-firmware-without-the-sysfs-fallb.patch @@ -0,0 +1,59 @@ +From 0509cfb2607a5a084617701f969b4bad0fd0f157 Mon Sep 17 00:00:00 2001 +From: Vitaliy Sochnev +Date: Fri, 7 Aug 2026 03:37:00 +0100 +Subject: [PATCH] net: airoha: npu: load the firmware without the sysfs + fallback + +airoha_npu_load_firmware() maps a missing firmware file to -EPROBE_DEFER +so that the NPU can be brought up once the rootfs carrying /lib/firmware +has been mounted. That mapping holds only as long as request_firmware() +reports -ENOENT. + +It does not when the sysfs fallback is in play. With +CONFIG_FW_LOADER_USER_HELPER_FALLBACK set, or with the fallback armed at +runtime through /proc/sys/kernel/firmware_config/force_sysfs_fallback, +request_firmware() hands the request to a userspace helper, waits out the +full loading_timeout and returns -ETIMEDOUT. The -ENOENT test no longer +matches, dev_err_probe() turns the result into a hard failure, and the +NPU is left unbound after stalling the boot for 60 seconds: + + airoha-npu 1e900000.npu: Direct firmware load for airoha/en7581_npu_rv32.bin failed with error -2 + airoha-npu 1e900000.npu: Falling back to sysfs fallback for: airoha/en7581_npu_rv32.bin + airoha-npu 1e900000.npu: error -ETIMEDOUT: failed to run npu firmware + airoha-npu 1e900000.npu: probe with driver airoha-npu failed with error -110 + +Clearing FW_LOADER_USER_HELPER in the configuration is not a dependable +guard against this, because unrelated drivers select it. On the affected +build the symbol was turned back on by LEDS_LP55XX_COMMON, even though +the platform had explicitly disabled it. + +request_firmware_direct() sets FW_OPT_NOFALLBACK_SYSFS, so a missing file +is reported as -ENOENT whatever the firmware loader is configured to do, +and the deferred probe path works as it was meant to. + +Measured on a Nokia XG-040G-MD with FW_LOADER_USER_HELPER=y and +FW_LOADER_USER_HELPER_FALLBACK=y, on two images from the same tree +differing only by this patch: without it the probe fails with +-ETIMEDOUT after 64.5s and the NPU stays unbound, with it the NPU +reports its firmware version at 3.7s. The fallback is compiled in and +forced in both cases; the patch does not disable it, it only keeps the +driver from falling into it. + +Fixes: 23290c7bc190 ("net: airoha: Introduce Airoha NPU support") +Cc: stable@vger.kernel.org +Signed-off-by: Vitaliy Sochnev +--- + drivers/net/ethernet/airoha/airoha_npu.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/net/ethernet/airoha/airoha_npu.c ++++ b/drivers/net/ethernet/airoha/airoha_npu.c +@@ -202,7 +202,7 @@ static int airoha_npu_load_firmware(stru + const struct firmware *fw; + int ret; + +- ret = request_firmware(&fw, fw_name, dev); ++ ret = request_firmware_direct(&fw, fw_name, dev); + if (ret) + return ret == -ENOENT ? -EPROBE_DEFER : ret; + -- 2.47.3