From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D28001862A for ; Mon, 28 Jul 2025 07:39:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=141.14.17.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753688400; cv=none; b=Nw7XwNQLAoTnNzHOMPA4Jg1Juxr7d6Vj1IPl4YH+2LAuIGCStqvtAJWss8QX9PAFDDjdT5Ot8ecv0m/rPqSKKfZArQSSjHKD5lQmf3JtVAp/nWwvjzJ2Gtdsz127jFMxxqmdCBWpgyEAanIPPjCvBgE6SFnidf6MEqGN6JuQXwE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753688400; c=relaxed/simple; bh=sEPblR3iWpobKqTK0HuO+9LpWsjdE5r1xMKXRFKQHBs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WjgMhk2FA3uu3VDFBsY4DPUS1eVHPvxGsD92QBGDxiD129y196okTPwXTk2nAz0z9Tc1poYLkLGPGxqvU3c0QMRB+Km5Q7beHt6oqVerE8RJQ3KBfELjQLEGxK+9DD64tYioUgQWnZxPuIWjLEd0o7kxWg3q8LF504KKCNf3O8s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de; spf=pass smtp.mailfrom=molgen.mpg.de; arc=none smtp.client-ip=141.14.17.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=molgen.mpg.de Received: from [192.168.2.202] (p57bd9d4f.dip0.t-ipconnect.de [87.189.157.79]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 93A1961E64849; Mon, 28 Jul 2025 09:39:06 +0200 (CEST) Message-ID: <4e5a3a4d-9b6b-443b-b3c2-eac1b44e96e0@molgen.mpg.de> Date: Mon, 28 Jul 2025 09:39:05 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: athk10: Poll service ready completion by default to avoid warning `failed to receive service ready completion, polling..`? To: Baochen Qiang Cc: Baochen Qiang , Jeff Johnson , ath10k@lists.infradead.org, James Prestwood , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , LKML References: <97a15967-5518-4731-a8ff-d43ff7f437b0@molgen.mpg.de> <3cbe13e1-a820-4804-a28c-a57e2ee7a020@oss.qualcomm.com> <8716a67c-6e33-4a35-8d96-33f81c07c8e0@molgen.mpg.de> <1e797dea-d2e1-4947-8ef3-d2ac5ea0c156@oss.qualcomm.com> Content-Language: en-US From: Paul Menzel In-Reply-To: <1e797dea-d2e1-4947-8ef3-d2ac5ea0c156@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit [CC: +scheduler folks for input on the wait_for_completion_timeout() part] Dear Baochen, Thank you for your reply. Am 28.07.25 um 04:18 schrieb Baochen Qiang: > On 7/25/2025 8:15 PM, Paul Menzel wrote: >> Am 22.07.25 um 11:38 schrieb Baochen Qiang: >> >>> On 7/22/2025 4:37 PM, Paul Menzel wrote: >> >>>> Today, on the Intel Kaby Lake laptop Dell XPS 13 9360 with >>>> >>>>      $ lspci -nn -s 3a: >>>>      3a:00.0 Network controller [0280]: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter [168c:003e] (rev 32) >>>> >>>> resuming from ACPI S3 took longer, as it sometimes does, and looking into this, I see >>>> `failed to receive service ready completion, polling..` after a delay of five seconds: >>>> >>>> ``` >>>> [    0.000000] Linux version 6.16.0-rc6-00253-g4871b7cb27f4 (build@bohemianrhapsody.molgen.mpg.de) (gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44) #90 SMP PREEMPT_DYNAMIC Sat Jul 19 08:53:39 CEST 2025 >>>> […] >>>> [    8.588020] abreu kernel: ath10k_pci 0000:3a:00.0: qca6174 hw3.2 target 0x05030000 chip_id 0x00340aff sub 1a56:1535 >>>> [    8.588372] abreu kernel: ath10k_pci 0000:3a:00.0: kconfig debug 0 debugfs 0 tracing 0 dfs 0 testmode 0 >>>> [    8.588603] abreu kernel: ath10k_pci 0000:3a:00.0: firmware ver WLAN.RM.4.4.1-00309- api 6 features wowlan,ignore-otp,mfp crc32 0793bcf2 >>>> […] >>>> [    9.113550] Bluetooth: hci0: QCA: patch rome 0x302 build 0x3e8, firmware rome 0x302 build 0x111 >>>> […] >>>> [41804.953487] PM: suspend entry (deep) >>>> [41804.988361] Filesystems sync: 0.034 seconds >>>> [41805.007216] Freezing user space processes >>>> [41805.009650] Freezing user space processes completed (elapsed 0.002 seconds) >>>> [41805.009663] OOM killer disabled. >>>> [41805.009666] Freezing remaining freezable tasks >>>> [41805.011383] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) >>>> [41805.011502] printk: Suspending console(s) (use no_console_suspend to debug) >>>> [41805.523883] ACPI: EC: interrupt blocked >>>> [41805.545779] ACPI: PM: Preparing to enter system sleep state S3 >>>> [41805.556040] ACPI: EC: event blocked >>>> [41805.556045] ACPI: EC: EC stopped >>>> [41805.556046] ACPI: PM: Saving platform NVS memory >>>> [41805.559408] Disabling non-boot CPUs ... >>>> [41805.562480] smpboot: CPU 3 is now offline >>>> [41805.567105] smpboot: CPU 2 is now offline >>>> [41805.572122] smpboot: CPU 1 is now offline >>>> [41805.582034] ACPI: PM: Low-level resume complete >>>> [41805.582079] ACPI: EC: EC started >>>> [41805.582080] ACPI: PM: Restoring platform NVS memory >>>> [41805.583986] Enabling non-boot CPUs ... >>>> [41805.584009] smpboot: Booting Node 0 Processor 1 APIC 0x2 >>>> [41805.584734] CPU1 is up >>>> [41805.584749] smpboot: Booting Node 0 Processor 2 APIC 0x1 >>>> [41805.585514] CPU2 is up >>>> [41805.585530] smpboot: Booting Node 0 Processor 3 APIC 0x3 >>>> [41805.586216] CPU3 is up >>>> [41805.589070] ACPI: PM: Waking up from system sleep state S3 >>>> [41805.623652] ACPI: EC: interrupt unblocked >>>> [41805.640074] ACPI: EC: event unblocked >>>> [41805.651951] nvme nvme0: 4/0/0 default/read/poll queues >>>> [41805.865391] atkbd serio0: Failed to deactivate keyboard on isa0060/serio0 >>>> [41810.933639] ath10k_pci 0000:3a:00.0: failed to receive service ready completion, polling.. >>>> [41810.933769] ath10k_pci 0000:3a:00.0: service ready completion received, continuing normally >>>> [41810.986330] OOM killer enabled. >>>> [41810.986332] Restarting tasks: Starting >>>> […] >>>> ``` >>>> >>>> Commit e57b7d62a1b2 (wifi: ath10k: poll service ready message before failing) [1][2], >>>> present since Linux v6.10-rc1, added this to avoid the hardware not being initialized: >>>> >>>>          time_left = wait_for_completion_timeout(&ar->wmi.service_ready, >>>>                                                  WMI_SERVICE_READY_TIMEOUT_HZ); >>>>          if (!time_left) { >>>>                  /* Sometimes the PCI HIF doesn't receive interrupt >>>>                   * for the service ready message even if the buffer >>>>                   * was completed. PCIe sniffer shows that it's >>>>                   * because the corresponding CE ring doesn't fires >>>>                   * it. Workaround here by polling CE rings once. >>>>                   */ >>>>                  ath10k_warn(ar, "failed to receive service ready completion, polling..\n"); >>>> >>>>                  for (i = 0; i < CE_COUNT; i++) >>>>                          ath10k_hif_send_complete_check(ar, i, 1); >>>> >>>>                  time_left = wait_for_completion_timeout(&ar->wmi.service_ready, >>>>                                                          WMI_SERVICE_READY_TIMEOUT_HZ); >>>>                  if (!time_left) { >>>>                          ath10k_warn(ar, "polling timed out\n"); >>>>                          return -ETIMEDOUT; >>>>                  } >>>> >>>>                  ath10k_warn(ar, "service ready completion received, continuing normally\n"); >>>>          } >>>> >>>> The comment says, it’s a hardware issue. I guess from the Qualcomm device and not the >>>> board design, as it happens with several devices like James’? >>>> >>>> Anyway, should polling be used by default then to avoid the delay? >>> >>> Adding additional polling before wait seems OK to me >> >> With the attached diff, I didn’t notice any issue on the Dell XPS 13 9360 with QCA6174. > > In the diff you are moving polling ahead of wait, IMO this might introduce some race: what > if hardware/firmware send the event right after polling is done? > > So how about, instead of moving, just adding a new polling before wait: > > 1. polling > 2. wait > 3. poling again if wait fail I do not know the hardware behavior/design and the error, so cannot judge, if a race would be possible. Could Qualcomm take over to cook up a patch I’d appreciated if Qualcomm could take over to cook up a patch, as you have the datasheets, erratas and a line to the hardware designers. >> Unrelated: The only thing I noticed is, that during boot (not resume) the function seems >> to be called twice. It looks like once for Wi-Fi and once for Bluetooth: >> >> ``` >> [   35.507604] ath10k_pci 0000:3a:00.0: board_file api 2 bmi_id N/A crc32 d2863f91 >> [   35.516010] usb 1-5: New USB device found, idVendor=0c45, idProduct=670c, bcdDevice=56.26 >> [   35.516022] usb 1-5: New USB device strings: Mfr=2, Product=1, SerialNumber=0 >> [   35.516026] usb 1-5: Product: Integrated_Webcam_HD >> [   35.516029] usb 1-5: Manufacturer: CN09GTFMLOG008C8B7FWA01 >> [   35.587852] ath10k_pci 0000:3a:00.0: service ready completion received, continuing normally >> [   35.606632] ath10k_pci 0000:3a:00.0: htt-ver 3.87 wmi-op 4 htt-op 3 cal otp max-sta 32 raw 0 hwcrypto 1 >> [   35.628744] mc: Linux media interface: v0.10 >> [   35.651301] nvme nvme0: using unchecked data buffer >> [   35.687466] Bluetooth: Core ver 2.22 >> [   35.687493] NET: Registered PF_BLUETOOTH protocol family >> [   35.687495] Bluetooth: HCI device and connection manager initialized >> [   35.687499] Bluetooth: HCI socket layer initialized >> [   35.687501] Bluetooth: L2CAP socket layer initialized >> [   35.687505] Bluetooth: SCO socket layer initialized >> [   35.696050] ath: EEPROM regdomain: 0x6c >> [   35.696055] ath: EEPROM indicates we should expect a direct regpair map >> [   35.696057] ath: Country alpha2 being used: 00 >> [   35.696058] ath: Regpair used: 0x6c >> [   35.712821] ath10k_pci 0000:3a:00.0 wlp58s0: renamed from wlan0 >> [   35.716790] input: ELAN Touchscreen as /devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4:1.0/0003:04F3:2234.0002/input/input40 >> [   35.718912] videodev: Linux video capture interface: v2.00 >> [   35.719492] input: ELAN Touchscreen UNKNOWN as /devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4:1.0/0003:04F3:2234.0002/input/input41 >> [   35.719595] input: ELAN Touchscreen UNKNOWN as /devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4:1.0/0003:04F3:2234.0002/input/input42 >> [   35.720899] hid-multitouch 0003:04F3:2234.0002: input,hiddev0,hidraw1: USB HID v1.10 Device [ELAN Touchscreen] on usb-0000:00:14.0-4/input0 >> [   35.720947] usbcore: registered new interface driver usbhid >> [   35.720949] usbhid: USB HID core driver >> [   35.812081] usbcore: registered new interface driver btusb >> [   35.815263] Bluetooth: hci0: using rampatch file: qca/rampatch_usb_00000302.bin >> [   35.815270] Bluetooth: hci0: QCA: patch rome 0x302 build 0x3e8, firmware rome 0x302 build 0x111 >> [   36.174345] Bluetooth: hci0: using NVM file: qca/nvm_usb_00000302.bin >> [   36.199643] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported. >> [   36.398657] ath10k_pci 0000:3a:00.0: service ready completion received, continuing normally > > Hmm, I don't think this is for BT as ath10k is not a BT driver. Something must be wrong > here ... > >> ``` Can you reproduce it? How would I get a call graph for both function calls? >>>> Additionally I have two questions regarding the code: >>>> >>>> 1.  Is `WMI_SERVICE_READY_TIMEOUT_HZ` the right value to pass to >>>> `wait_for_completion_timeout(struct completion *done, unsigned long timeout)`? >>>> >>>> The macro is defined as: >>>> >>>>      drivers/net/wireless/ath/ath10k/wmi.h:#define WMI_SERVICE_READY_TIMEOUT_HZ (5 * HZ) >>>> >>>> `timeout` is supposed to be in jiffies, and `CONFIG_HZ_250=y` on my system. I wonder how >>>> that amounts to five seconds on my system. >>> >>> HZ is defined as jiffies per second, so 5 * HZ equals 5 seconds. Sorry, I missed to comment here in my previous reply. HZ can be defined differently – like 1000 HZ –, so the timeout would very, and then not match the actual timeout required by the hardware? `Documentation/scheduler/completion.rst` contains: > Timeouts are preferably calculated with msecs_to_jiffies() or usecs_to_jiffies(), > to make the code largely HZ-invariant. >>>> The timeout should probably be defined in seconds? Does the WMI specification say >>>> something about this? >>>> >>>> 2.  Is the task interruptable and should `wait_for_completion_interruptible_timeout(struct >>>> completion *done, unsigned long timeout)` be used? >>> >>> While I am not sure for now, may I ask why the question? >> >> I was just reading up on `wait_for_completion_*()`, and so the different variants. > > If there is no obvious benefits I don't think the change is necessary. Thinking about it, the driver initialization is in the boot path (hot patch) so would block one thread(?) – or is that a wrong assumption –, which is unwanted? Kind regards, Paul >>>> [1]: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e57b7d62a1b2f496caf0beba81cec3c90fad80d5 >>>> [2]: https://lore.kernel.org/all/20240227030409.89702-1-quic_bqiang@quicinc.com/