From: Laura Abbott Date: Tue, 28 Apr 2015 15:37:44 -0700 Subject: [PATCH] firmware: Drop WARN from usermodehelper_read_trylock error case We've received a number of reports of warnings when coming out of suspend with certain bluetooth firmware configurations: WARNING: CPU: 3 PID: 3280 at drivers/base/firmware_class.c:1126 _request_firmware+0x558/0x810() Modules linked in: ccm ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw binfmt_misc bnep intel_rapl iosf_mbi arc4 x86_pkg_temp_thermal snd_hda_codec_hdmi coretemp kvm_intel joydev snd_hda_codec_realtek iwldvm snd_hda_codec_generic kvm iTCO_wdt mac80211 iTCO_vendor_support snd_hda_intel snd_hda_controller snd_hda_codec crct10dif_pclmul snd_hwdep crc32_pclmul snd_seq crc32c_intel ghash_clmulni_intel uvcvideo snd_seq_device iwlwifi btusb videobuf2_vmalloc snd_pcm videobuf2_core serio_raw bluetooth cfg80211 videobuf2_memops sdhci_pci v4l2_common videodev thinkpad_acpi sdhci i2c_i801 lpc_ich mfd_core wacom mmc_core media snd_timer tpm_tis hid_logitech_hidpp wmi tpm rfkill snd mei_me mei shpchp soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc i915 i2c_algo_bit drm_kms_helper e1000e drm hid_logitech_dj ptp pps_core video CPU: 3 PID: 3280 Comm: kworker/u17:0 Not tainted 3.19.3-200.fc21.x86_64 Hardware name: LENOVO 343522U/343522U, BIOS GCET96WW (2.56 ) 10/22/2013 Workqueue: hci0 hci_power_on [bluetooth] 0000000000000000 0000000089944328 ffff88040acffb78 ffffffff8176e215 0000000000000000 0000000000000000 ffff88040acffbb8 ffffffff8109bc1a 0000000000000000 ffff88040acffcd0 00000000fffffff5 ffff8804076bac40 Call Trace: [] dump_stack+0x45/0x57 [] warn_slowpath_common+0x8a/0xc0 [] warn_slowpath_null+0x1a/0x20 [] _request_firmware+0x558/0x810 [] request_firmware+0x35/0x50 [] btusb_setup_bcm_patchram+0x86/0x590 [btusb] [] ? rpm_idle+0xd6/0x230 [] hci_dev_do_open+0xe1/0xa90 [bluetooth] [] ? ttwu_do_activate.constprop.90+0x5d/0x70 [] hci_power_on+0x40/0x200 [bluetooth] [] process_one_work+0x14c/0x3f0 [] worker_thread+0x53/0x470 [] ? rescuer_thread+0x300/0x300 [] kthread+0xd8/0xf0 [] ? kthread_create_on_node+0x1b0/0x1b0 [] ret_from_fork+0x58/0x90 [] ? kthread_create_on_node+0x1b0/0x1b0 This occurs after every resume. When resuming, the bluetooth driver needs to re-request the firmware. This re-request is happening before usermodehelper is fully enabled. If the firmware load succeeded previously, the caching behavior of the firmware code typically negates the need to call the usermodehelper code again and the request succeeds. If the firmware was never loaded because it isn't actually present in the file system, this results in a call to usermodehelper and a failure warning every resume. The proper fix is to add a reset_resume functionality to the btusb driver to be able to handle the resume case. The work for this is ongoing so in the mean time just silence the warning since we know it's a problem. Bugzilla: 1133378 Upstream-status: Working on it. It's a difficult problem :( Signed-off-by: Laura Abbott --- drivers/base/firmware_class.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 894bda114224..f7a8d27b6459 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1144,7 +1144,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name, } } else { ret = usermodehelper_read_trylock(); - if (WARN_ON(ret)) { + if (ret) { dev_err(device, "firmware: %s will not be loaded\n", name); goto out;