From patchwork Sat Jul 15 21:18:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 9842523 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1D384602D8 for ; Sat, 15 Jul 2017 21:19:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0FB95285C8 for ; Sat, 15 Jul 2017 21:19:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0465D285D5; Sat, 15 Jul 2017 21:19:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 80DC2285C8 for ; Sat, 15 Jul 2017 21:19:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751257AbdGOVTG (ORCPT ); Sat, 15 Jul 2017 17:19:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:52102 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252AbdGOVTC (ORCPT ); Sat, 15 Jul 2017 17:19:02 -0400 Received: from garbanzo.do-not-panic.com (c-73-15-241-2.hsd1.ca.comcast.net [73.15.241.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C973B23693; Sat, 15 Jul 2017 21:19:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C973B23693 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mcgrof@kernel.org From: "Luis R. Rodriguez" To: gregkh@linuxfoundation.org Cc: wagi@monom.org, yi1.li@linux.intel.com, takahiro.akashi@linaro.org, bjorn.andersson@linaro.org, luto@kernel.org, ebiederm@xmission.com, dmitry.torokhov@gmail.com, arend.vanspriel@broadcom.com, dwmw2@infradead.org, rjw@rjwysocki.net, atull@kernel.org, moritz.fischer@ettus.com, pmladek@suse.com, johannes.berg@intel.com, emmanuel.grumbach@intel.com, luciano.coelho@intel.com, kvalo@codeaurora.org, torvalds@linux-foundation.org, keescook@chromium.org, dhowells@redhat.com, pjones@redhat.com, hdegoede@redhat.com, alan@linux.intel.com, tytso@mit.edu, dave@stgolabs.net, mawilcox@microsoft.com, tglx@linutronix.de, peterz@infradead.org, mfuzzey@parkeon.com, jakub.kicinski@netronome.com, nbroeking@me.com, jewalt@lgsinnovations.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" , "stable # v3 . 14" Subject: [PATCH 4/4] firmware: fix batched requests: send wake up on failure on direct lookups Date: Sat, 15 Jul 2017 14:18:53 -0700 Message-Id: <20170715211853.17457-5-mcgrof@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170715211853.17457-1-mcgrof@kernel.org> References: <20170715211853.17457-1-mcgrof@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Fix batched requests from waiting forever on failure. The firmware API batched requests feature has been broken since the API call request_firmware_direct() was introduced on commit bba3a87e982ad ("firmware: Introduce request_firmware_direct()"), added on v3.14 *iff* the firmware being requested was not present in *certail kernel builds* [0]. When no firmware is found the worker which goes on to finish never informs waiters queued up of this, so any batched request will stall in what seems to be forever (MAX_SCHEDULE_TIMEOUT). Sadly, a reboot will also stall, as the reboot notifier was only designed to kill custom fallback workers. The issue seems to the user as a type of soft lockup, what *actually* happens underneath the hood is a wait call which never completes as we failed to issue a completion on error. For device drivers with optional firmware schemes (ie, Intel iwlwifi, or Netronome -- even though it uses request_firmware() and not request_firmware_direct()), this could mean that when you boot a system with multiple cards the firmware will seem to never load on the system, or that the card is just not responsive even the driver initialization. Due to differences in scheduling possible this should not always trigger -- one would need to to ensure that multiple requests are in place at the right time for this to work, also release_firmware() must not be called prior to any other incoming request. The complexity may not be worth supporting batched requests in the future given the wait mechanism is only used also for the fallback mechanism. We'll keep it for now and just fix it. Its reported that at least with the Intel WiFi cards on one system this issue was creeping up 50% of the boots [0]. Ater this commit batched testing results: ============================================================================ CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n CONFIG_FW_LOADER_USER_HELPER=y Most common Linux distribution setup. API-type no-firmware-found firmware-found ---------------------------------------------------------------------- request_firmware() OK OK request_firmware_direct() OK OK request_firmware_nowait(uevent=true) OK OK request_firmware_nowait(uevent=false) OK OK ============================================================================ CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n CONFIG_FW_LOADER_USER_HELPER=n Only possible if CONFIG_DELL_RBU=n and CONFIG_LEDS_LP55XX_COMMON=n, rare. API-type no-firmware-found firmware-found ---------------------------------------------------------------------- request_firmware() OK OK request_firmware_direct() OK OK request_firmware_nowait(uevent=true) OK OK request_firmware_nowait(uevent=false) OK OK ============================================================================ CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y CONFIG_FW_LOADER_USER_HELPER=y Google Android setup. API-type no-firmware-found firmware-found ---------------------------------------------------------------------- request_firmware() OK OK request_firmware_direct() OK OK request_firmware_nowait(uevent=true) OK OK request_firmware_nowait(uevent=false) OK OK ============================================================================ [0] https://bugzilla.kernel.org/show_bug.cgi?id=195477 Cc: stable # v3.14 Fixes: bba3a87e982ad ("firmware: Introduce request_firmware_direct()" Reported-by: Nicolas Reported-by: John Ewalt Reported-by: Jakub Kicinski Signed-off-by: Luis R. Rodriguez --- drivers/base/firmware_class.c | 38 ++++++++++++++++++++++++++++++-------- 1 file changed, 30 insertions(+), 8 deletions(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index a85dabeb1e20..a5fb884a136d 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -154,28 +154,27 @@ static void __fw_state_set(struct fw_state *fw_st, __fw_state_set(fw_st, FW_STATUS_LOADING) #define fw_state_done(fw_st) \ __fw_state_set(fw_st, FW_STATUS_DONE) +#define fw_state_aborted(fw_st) \ + __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_wait(fw_st) \ __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT) -#ifndef CONFIG_FW_LOADER_USER_HELPER - -#define fw_state_is_aborted(fw_st) false - -#else /* CONFIG_FW_LOADER_USER_HELPER */ - static int __fw_state_check(struct fw_state *fw_st, enum fw_status status) { return fw_st->status == status; } +#define fw_state_is_aborted(fw_st) \ + __fw_state_check(fw_st, FW_STATUS_ABORTED) + +#ifdef CONFIG_FW_LOADER_USER_HELPER + #define fw_state_aborted(fw_st) \ __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_is_done(fw_st) \ __fw_state_check(fw_st, FW_STATUS_DONE) #define fw_state_is_loading(fw_st) \ __fw_state_check(fw_st, FW_STATUS_LOADING) -#define fw_state_is_aborted(fw_st) \ - __fw_state_check(fw_st, FW_STATUS_ABORTED) #define fw_state_wait_timeout(fw_st, timeout) \ __fw_state_wait_common(fw_st, timeout) @@ -1204,6 +1203,28 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name, return 1; /* need to load */ } +/* + * Batched requests need only one wake, we need to do this step last due to the + * fallback mechanism. The buf is protected with kref_get(), and it won't be + * released until the last user calls release_firmware(). + * + * Failed batched requests are possible as well, in such cases we just share + * the struct firmware_buf and won't release it until all requests are woken + * and have gone through this same path. + */ +static void fw_abort_batch_reqs(struct firmware *fw) +{ + struct firmware_buf *buf; + + /* Loaded directly? */ + if (!fw || !fw->priv) + return; + + buf = fw->priv; + if (!fw_state_is_aborted(&buf->fw_st)) + fw_state_aborted(&buf->fw_st); +} + /* called from request_firmware() and request_firmware_work_func() */ static int _request_firmware(const struct firmware **firmware_p, const char *name, @@ -1247,6 +1268,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name, out: if (ret < 0) { + fw_abort_batch_reqs(fw); release_firmware(fw); fw = NULL; }