Re: [PATCH v2] ath10k: skip ath10k_halt during suspend for driver state RESTARTING

From: Kalle Valo <kvalo@kernel.org>
To: Abhishek Kumar <kuabhs@chromium.org>
Cc: quic_wgong@quicinc.com, kuabhs@chromium.org,
	briannorris@chromium.org, linux-kernel@vger.kernel.org,
	linux-wireless@vger.kernel.org, ath10k@lists.infradead.org,
	netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Subject: Re: [PATCH v2] ath10k: skip ath10k_halt during suspend for driver state RESTARTING
Date: Fri, 29 Apr 2022 06:06:25 +0000 (UTC)	[thread overview]
Message-ID: <165121238072.2322.15176530222754995177.kvalo@kernel.org> (raw)
In-Reply-To: <20220426221859.v2.1.I650b809482e1af8d0156ed88b5dc2677a0711d46@changeid>

Abhishek Kumar <kuabhs@chromium.org> wrote:

> Double free crash is observed when FW recovery(caused by wmi
> timeout/crash) is followed by immediate suspend event. The FW recovery
> is triggered by ath10k_core_restart() which calls driver clean up via
> ath10k_halt(). When the suspend event occurs between the FW recovery,
> the restart worker thread is put into frozen state until suspend completes.
> The suspend event triggers ath10k_stop() which again triggers ath10k_halt()
> The double invocation of ath10k_halt() causes ath10k_htt_rx_free() to be
> called twice(Note: ath10k_htt_rx_alloc was not called by restart worker
> thread because of its frozen state), causing the crash.
> 
> To fix this, during the suspend flow, skip call to ath10k_halt() in
> ath10k_stop() when the current driver state is ATH10K_STATE_RESTARTING.
> Also, for driver state ATH10K_STATE_RESTARTING, call
> ath10k_wait_for_suspend() in ath10k_stop(). This is because call to
> ath10k_wait_for_suspend() is skipped later in
> [ath10k_halt() > ath10k_core_stop()] for the driver state
> ATH10K_STATE_RESTARTING.
> 
> The frozen restart worker thread will be cancelled during resume when the
> device comes out of suspend.
> 
> Below is the crash stack for reference:
> 
> [  428.469167] ------------[ cut here ]------------
> [  428.469180] kernel BUG at mm/slub.c:4150!
> [  428.469193] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> [  428.469219] Workqueue: events_unbound async_run_entry_fn
> [  428.469230] RIP: 0010:kfree+0x319/0x31b
> [  428.469241] RSP: 0018:ffffa1fac015fc30 EFLAGS: 00010246
> [  428.469247] RAX: ffffedb10419d108 RBX: ffff8c05262b0000
> [  428.469252] RDX: ffff8c04a8c07000 RSI: 0000000000000000
> [  428.469256] RBP: ffffa1fac015fc78 R08: 0000000000000000
> [  428.469276] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  428.469285] Call Trace:
> [  428.469295]  ? dma_free_attrs+0x5f/0x7d
> [  428.469320]  ath10k_core_stop+0x5b/0x6f
> [  428.469336]  ath10k_halt+0x126/0x177
> [  428.469352]  ath10k_stop+0x41/0x7e
> [  428.469387]  drv_stop+0x88/0x10e
> [  428.469410]  __ieee80211_suspend+0x297/0x411
> [  428.469441]  rdev_suspend+0x6e/0xd0
> [  428.469462]  wiphy_suspend+0xb1/0x105
> [  428.469483]  ? name_show+0x2d/0x2d
> [  428.469490]  dpm_run_callback+0x8c/0x126
> [  428.469511]  ? name_show+0x2d/0x2d
> [  428.469517]  __device_suspend+0x2e7/0x41b
> [  428.469523]  async_suspend+0x1f/0x93
> [  428.469529]  async_run_entry_fn+0x3d/0xd1
> [  428.469535]  process_one_work+0x1b1/0x329
> [  428.469541]  worker_thread+0x213/0x372
> [  428.469547]  kthread+0x150/0x15f
> [  428.469552]  ? pr_cont_work+0x58/0x58
> [  428.469558]  ? kthread_blkcg+0x31/0x31
> 
> Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1
> Co-developed-by: Wen Gong <quic_wgong@quicinc.com>
> Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
> Signed-off-by: Abhishek Kumar <kuabhs@chromium.org>
> Reviewed-by: Brian Norris <briannorris@chromium.org>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Patch applied to ath-next branch of ath.git, thanks.

b72a4aff947b ath10k: skip ath10k_halt during suspend for driver state RESTARTING

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20220426221859.v2.1.I650b809482e1af8d0156ed88b5dc2677a0711d46@changeid/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches