From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hL7Dt-0000ox-G9 for ath10k@lists.infradead.org; Mon, 29 Apr 2019 14:25:39 +0000 MIME-Version: 1.0 Subject: Re: [PATCH for-5.1] ath10k: perform crash dump collection in workqueue From: Kalle Valo In-Reply-To: <20190326205728.168973-1-briannorris@chromium.org> References: <20190326205728.168973-1-briannorris@chromium.org> Message-Id: <20190429142537.2614F60131@smtp.codeaurora.org> Date: Mon, 29 Apr 2019 14:25:37 +0000 (UTC) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Brian Norris Cc: Carl Huang , linux-wireless@vger.kernel.org, ath10k@lists.infradead.org, Wen Gong , =?utf-8?q?Micha=C5=82_Kazior?= Brian Norris wrote: > Commit 25733c4e67df ("ath10k: pci: use mutex for diagnostic window CE > polling") introduced a regression where we try to sleep (grab a mutex) > in an atomic context: > > [ 233.602619] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254 > [ 233.602626] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0 > [ 233.602636] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.1.0-rc2 #4 > [ 233.602642] Hardware name: Google Scarlet (DT) > [ 233.602647] Call trace: > [ 233.602663] dump_backtrace+0x0/0x11c > [ 233.602672] show_stack+0x20/0x28 > [ 233.602681] dump_stack+0x98/0xbc > [ 233.602690] ___might_sleep+0x154/0x16c > [ 233.602696] __might_sleep+0x78/0x88 > [ 233.602704] mutex_lock+0x2c/0x5c > [ 233.602717] ath10k_pci_diag_read_mem+0x68/0x21c [ath10k_pci] > [ 233.602725] ath10k_pci_diag_read32+0x48/0x74 [ath10k_pci] > [ 233.602733] ath10k_pci_dump_registers+0x5c/0x16c [ath10k_pci] > [ 233.602741] ath10k_pci_fw_crashed_dump+0xb8/0x548 [ath10k_pci] > [ 233.602749] ath10k_pci_napi_poll+0x60/0x128 [ath10k_pci] > [ 233.602757] net_rx_action+0x140/0x388 > [ 233.602766] __do_softirq+0x1b0/0x35c > [...] > > ath10k_pci_fw_crashed_dump() is called from NAPI contexts, and firmware > memory dumps are retrieved using the diag memory interface. > > A simple reproduction case is to run this on QCA6174A / > WLAN.RM.4.4.1-00132-QCARMSWP-1, which happens to be a way to b0rk the > firmware: > > dd if=/sys/kernel/debug/ieee80211/phy0/ath10k/mem_value bs=4K count=1 > of=/dev/null > > (NB: simulated firmware crashes, via debugfs, don't trigger firmware > dumps.) > > The fix is to move the crash-dump into a workqueue context, and avoid > relying on 'data_lock' for most mutual exclusion. We only keep using it > here for protecting 'fw_crash_counter', while the rest of the coredump > buffers are protected by a new 'dump_mutex'. > > I've tested the above with simulated firmware crashes (debugfs 'reset' > file), real firmware crashes (the 'dd' command above), and a variety of > reboot and suspend/resume configurations on QCA6174A. > > Reported here: > http://lkml.kernel.org/linux-wireless/20190325202706.GA68720@google.com > > Fixes: 25733c4e67df ("ath10k: pci: use mutex for diagnostic window CE polling") > Signed-off-by: Brian Norris > Signed-off-by: Kalle Valo Patch applied to ath-current branch of ath.git, thanks. 38faed150438 ath10k: perform crash dump collection in workqueue -- https://patchwork.kernel.org/patch/10872181/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k