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Date:   Fri, 22 Sep 2023 09:36:55 -0700
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Subject: Re: [RFC] ata: libata: increase PMP SRST timeout to 10s
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To:     Matthias Schiffer <mschiffer@universe-factory.net>
Cc:     linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
References: <dcbe606ac716e01f103f8aa62f0201cdb8f3efa0.1695394865.git.mschiffer@universe-factory.net>
From:   Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
In-Reply-To: <dcbe606ac716e01f103f8aa62f0201cdb8f3efa0.1695394865.git.mschiffer@universe-factory.net>
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On 2023/09/22 9:18, Matthias Schiffer wrote:
> On certain devices(*), this device probe failures for SATA disks after
> wakeup from S2RAM, which often led to the disks not to be detected again.
> 
>     ata1: softreset failed (1st FIS failed)
> 
> (*) Observed for disks connected to the internal SATA controller of the
> QNAP TS-453B, which is a "SATA controller: Intel Corporation
> Celeron/Pentium Silver Processor SATA Controller (rev 06)".
> 
> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
> ---
> 
> I'm sending this as an RFC, as I don't think it makes sense to increase the
> timeout unconditionally - maybe it should be some kind of device quirk, if
> there isn't any better fix.
> 
> See text below for more information.
> 
>  include/linux/libata.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index be2f0cee1601..9194030527b6 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -256,7 +256,7 @@ enum {
>  	 * advised to wait only for the following duration before
>  	 * doing SRST.
>  	 */
> -	ATA_TMOUT_PMP_SRST_WAIT	= 5000,
> +	ATA_TMOUT_PMP_SRST_WAIT	= 10000,
>  
>  	/* When the LPM policy is set to ATA_LPM_MAX_POWER, there might
>  	 * be a spurious PHY event, so ignore the first PHY event that
> ---
> 
> I'm running plain Debian 12 rather than the QNAP OS (I believe the original
> software does not support S2RAM at all). The issue I'm describing exists at
> least since kernel 5.15; I've never run older kernels on this hardware. The
> mainboard has 2 SATA controllers, both handled by the ahci driver:
> 
>     # lspci | grep SATA
>     00:12.0 SATA controller: Intel Corporation Celeron/Pentium Silver Processor SATA Controller (rev 06)
>     02:00.0 SATA controller: ASMedia Technology Inc. 106x SATA/RAID Controller (rev 01)
> 
> The first two channels ata1 and ata2 are connected to the Intel controller,
> while the ASMedia is responsible for ata3 through ata14. I have the same hard
> drives connected to ata2, ata3, and ata4 (ata1 has a different model), and I'm
> seeing the timeout issue after suspend only on ata1 and ata2, so it is specific
> to the Intel controller rather than the drive model.
> 
> On Debian's default 6.1.52 kernel, a wakeup looks like the following *in the
> good case*, where all disks are successfully brought up again (unfortunately,
> journald doesn't seem to have recorded correct timing information; roughly
> 22 seconds pass between the "starting disk" and final "link up"). I have
> redacted lines for the unused ata{5..14} ports for conciseness.
> 
>     ACPI: PM: Waking up from system sleep state S3
>     sd 2:0:0:0: [sdc] Starting disk
>     sd 3:0:0:0: [sdd] Starting disk
>     sd 1:0:0:0: [sdb] Starting disk
>     sd 0:0:0:0: [sda] Starting disk
>     ata3: link is slow to respond, please be patient (ready=0)
>     ata4: link is slow to respond, please be patient (ready=0)
>     ata2: found unknown device (class 0)
>     ata1: found unknown device (class 0)
>     ata1: softreset failed (1st FIS failed)
>     ata2: softreset failed (1st FIS failed)
>     ata3: COMRESET failed (errno=-16)
>     ata4: COMRESET failed (errno=-16)
>     ata1: found unknown device (class 0)
>     ata2: found unknown device (class 0)
>     ata3: link is slow to respond, please be patient (ready=0)
>     ata4: link is slow to respond, please be patient (ready=0)
>     ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata3.00: configured for UDMA/133
>     ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata4.00: configured for UDMA/133
>     ata1: softreset failed (1st FIS failed)
>     ata2: softreset failed (1st FIS failed)
>     ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata2.00: configured for UDMA/133
>     ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata1.00: configured for UDMA/133
> 
> On the same kernel, another wakeup might look like this:
> 
>     ACPI: PM: Waking up from system sleep state S3
>     sd 2:0:0:0: [sdd] Starting disk
>     sd 3:0:0:0: [sdc] Starting disk
>     sd 0:0:0:0: [sda] Starting disk
>     sd 1:0:0:0: [sdb] Starting disk
>     ata2: SATA link down (SStatus 0 SControl 300)
>     ata3: link is slow to respond, please be patient (ready=0)
>     ata4: link is slow to respond, please be patient (ready=0)
>     ata1: SATA link down (SStatus 0 SControl 300)
>     ata3: COMRESET failed (errno=-16)
>     ata4: COMRESET failed (errno=-16)
>     ata1: SATA link down (SStatus 0 SControl 300)
>     ata1: limiting SATA link speed to <unknown>
>     ata3: link is slow to respond, please be patient (ready=0)
>     ata4: link is slow to respond, please be patient (ready=0)
>     ata2: SATA link down (SStatus 0 SControl 300)
>     ata2: limiting SATA link speed to <unknown>
>     ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     ata3.00: configured for UDMA/133
>     ata4.00: configured for UDMA/133
>     ata1: SATA link down (SStatus 0 SControl 3F0)
>     ata1.00: disable device
>     ata2: SATA link down (SStatus 0 SControl 3F0)
>     ata2.00: disable device
>     sd 1:0:0:0: rejecting I/O to offline device
>     sd 0:0:0:0: rejecting I/O to offline device
>     ata2.00: detaching (SCSI 1:0:0:0)
>     ata1.00: detaching (SCSI 0:0:0:0)
>     sd 0:0:0:0: [sda] Start/Stop Unit failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
>     sd 1:0:0:0: [sdb] Start/Stop Unit failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
>     sd 0:0:0:0: PM: dpm_run_callback(): scsi_bus_resume+0x0/0x90 [scsi_mod] returns -5
>     sd 1:0:0:0: PM: dpm_run_callback(): scsi_bus_resume+0x0/0x90 [scsi_mod] returns -5
>     sd 0:0:0:0: PM: failed to resume async: error -5
>     sd 1:0:0:0: PM: failed to resume async: error -5
> 
> With my patch applied, the following log is generated instead:
> 
>     [   63.748299] ACPI: PM: Waking up from system sleep state S3
>     [   63.767111] sd 2:0:0:0: [sdc] Starting disk
>     [   63.767181] sd 3:0:0:0: [sdd] Starting disk
>     [   63.776402] sd 0:0:0:0: [sdb] Starting disk
>     [   63.776500] sd 1:0:0:0: [sda] Starting disk
>     [   69.121513] ata4: link is slow to respond, please be patient (ready=0)
>     [   69.125531] ata3: link is slow to respond, please be patient (ready=0)
>     [   69.133538] ata2: link is slow to respond, please be patient (ready=0)
>     [   69.133557] ata1: link is slow to respond, please be patient (ready=0)
>     [   73.803763] ata4: COMRESET failed (errno=-16)
>     [   73.807805] ata3: COMRESET failed (errno=-16)
>     [   73.815780] ata2: found unknown device (class 0)
>     [   73.815800] ata1: found unknown device (class 0)
>     [   73.975799] ata2: softreset failed (device not ready)
>     [   73.975813] ata1: softreset failed (device not ready)
>     [   79.157124] ata4: link is slow to respond, please be patient (ready=0)
>     [   79.161116] ata3: link is slow to respond, please be patient (ready=0)
>     [   79.329119] ata1: link is slow to respond, please be patient (ready=0)
>     [   79.329129] ata2: link is slow to respond, please be patient (ready=0)
>     [   80.781376] ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     [   80.792790] ata3.00: configured for UDMA/133
>     [   80.837437] ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     [   80.843358] ata4.00: configured for UDMA/133
>     [   82.309565] ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     [   82.334217] ata2.00: configured for UDMA/133
>     [   84.009745] ata1: found unknown device (class 0)
>     [   84.169743] ata1: softreset failed (device not ready)
>     [   85.425859] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     [   85.486518] ata1.00: configured for UDMA/133
> 
> Compared to the previous "good" log
> - ata1 and ata2 got "link is slow to respond" messages
> - the "softreset failed" error changed from "1st FIS failed" to "device not
>   ready"
> - I haven't seen any failures to bring up drives in 10+ wakeups, where it would
>   fail in roughly 1 out of 3 tries without the increased timeout
> 
> I also saw the resume improvements going on in
> https://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata.git/, so next I
> took kernel 6.5.4 and applied all patches from the for-6.6 and for-6.7 branches
> from that repo on top. The first thing I noticed with this new kernel was a
> regression:
> 
>     16:24:25 : PM: suspend exit
>     16:24:25 : ata2: SATA link down (SStatus 0 SControl 300)
>     16:24:25 : ata2.00: Entering active power mode
>     16:24:25 : ata1: SATA link down (SStatus 0 SControl 300)
>     16:24:25 : ata1.00: Entering active power mode
>     16:24:30 : ata3: link is slow to respond, please be patient (ready=0)
>     16:24:30 : ata4: link is slow to respond, please be patient (ready=0)
>     16:24:35 : ata2.00: qc timeout after 10000 msecs (cmd 0x40)
>     16:24:35 : ata1.00: qc timeout after 10000 msecs (cmd 0x40)
>     16:24:35 : ata1.00: VERIFY failed (err_mask=0x4)
>     16:24:35 : ata2.00: VERIFY failed (err_mask=0x4)
>     16:24:35 : ata2: SATA link down (SStatus 0 SControl 300)
>     16:24:35 : ata2: limiting SATA link speed to <unknown>
>     16:24:41 : ata4: link is slow to respond, please be patient (ready=0)
>     16:24:41 : ata3: link is slow to respond, please be patient (ready=0)
>     16:24:41 : ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:24:41 : ata4.00: Entering active power mode
>     16:24:41 : ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:24:41 : ata3.00: Entering active power mode
>     16:24:41 : ata4.00: configured for UDMA/133
>     16:24:41 : ata3.00: configured for UDMA/133
>     16:24:41 : ata1: SATA link down (SStatus 0 SControl 300)
>     16:24:41 : ata1: limiting SATA link speed to <unknown>
>     16:24:47 : ata1: SATA link down (SStatus 0 SControl 3F0)
>     16:24:47 : ata1.00: disable device
>     16:24:47 : ata2: SATA link down (SStatus 0 SControl 3F0)
>     16:24:47 : ata2.00: disable device
>     16:24:47 : ata1.00: detaching (SCSI 0:0:0:0)
>     16:24:47 : ata2.00: detaching (SCSI 1:0:0:0)
> 
> For the ASMedia controller, the new kernel fixes the "COMRESET failed" messages,
> but on the Intel controller, two new errors have appeared ("qc timeout" and
> "VERIFY failed"), and my drives are missing again.

These errors are being address by a series that is about to be applied:

https://lore.kernel.org/linux-ide/yq134z7577n.fsf@ca-mkp.ca.oracle.com/T/#m255ef5cc9b64b971765e8b6551aacee860fd1325

This series addresses various issues with libata resume, including what you are
seeing above, which causes the drives to fail resume and disappear, or worth, a
hang on resume. Could you please try to apply these patches and test with them ?
The "link is slow to respond" message is fairly normal and overall, there is up
to 1min timeout before giving up on the drive. So this should not be an issue.

If you still see a problem with your system, we can increase the timeout to
avoid that "1st FIS failed" error.

> 
> The new messages could be fixed by adding libata.ata_probe_timeout=30 to the
> cmdline; I still consider this a regression, as it wasn't necessary before.
> With the added cmdline:
> 
>     16:34:17 : PM: suspend exit
>     16:34:22 : ata3: link is slow to respond, please be patient (ready=0)
>     16:34:22 : ata4: link is slow to respond, please be patient (ready=0)
>     16:34:22 : ata2: found unknown device (class 0)
>     16:34:22 : ata1: found unknown device (class 0)
>     16:34:27 : ata1: softreset failed (1st FIS failed)
>     16:34:27 : ata2: softreset failed (1st FIS failed)
>     16:34:32 : ata1: found unknown device (class 0)
>     16:34:32 : ata2: found unknown device (class 0)
>     16:34:32 : ata3: link is slow to respond, please be patient (ready=0)
>     16:34:32 : ata4: link is slow to respond, please be patient (ready=0)
>     16:34:35 : ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:34:35 : ata3.00: Entering active power mode
>     16:34:35 : ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:34:35 : ata4.00: Entering active power mode
>     16:34:35 : ata3.00: configured for UDMA/133
>     16:34:35 : ata4.00: configured for UDMA/133
>     16:34:37 : ata1: softreset failed (1st FIS failed)
>     16:34:37 : ata2: softreset failed (1st FIS failed)
>     16:34:38 : ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:34:38 : ata2.00: Entering active power mode
>     16:34:38 : ata2.00: configured for UDMA/133
>     16:34:40 : ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:34:40 : ata1.00: Entering active power mode
>     16:34:40 : ata1.00: configured for UDMA/133
> 
> Okay, we're back at the "1st FIS failed" message. I actually haven't tried
> suspending with this kernel a lot, so I don't know how often my drives would
> go missing in this setup, but I assume it's similar to kernel 6.1 (the first
> two logs I posted), as the error messages look the same.
> 
> Finally, I took that last kernel and also applied my timeout increase patch on
> top, resulting in the following log:
> 
>     16:48:33 : PM: suspend exit
>     16:48:39 : ata3: link is slow to respond, please be patient (ready=0)
>     16:48:39 : ata4: link is slow to respond, please be patient (ready=0)
>     16:48:39 : ata2: link is slow to respond, please be patient (ready=0)
>     16:48:39 : ata1: link is slow to respond, please be patient (ready=0)
>     16:48:43 : ata1: found unknown device (class 0)
>     16:48:43 : ata2: found unknown device (class 0)
>     16:48:44 : ata2: softreset failed (device not ready)
>     16:48:44 : ata1: softreset failed (device not ready)
>     16:48:49 : ata4: link is slow to respond, please be patient (ready=0)
>     16:48:49 : ata3: link is slow to respond, please be patient (ready=0)
>     16:48:49 : ata2: link is slow to respond, please be patient (ready=0)
>     16:48:49 : ata1: link is slow to respond, please be patient (ready=0)
>     16:48:51 : ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:48:51 : ata3.00: Entering active power mode
>     16:48:51 : ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:48:51 : ata4.00: Entering active power mode
>     16:48:51 : ata3.00: configured for UDMA/133
>     16:48:51 : ata4.00: configured for UDMA/133
>     16:48:52 : ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:48:52 : ata2.00: Entering active power mode
>     16:48:52 : ata2.00: configured for UDMA/133
>     16:48:54 : ata1: found unknown device (class 0)
>     16:48:54 : ata1: softreset failed (device not ready)
>     16:48:56 : ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>     16:48:56 : ata1.00: Entering active power mode
>     16:48:56 : ata1.00: configured for UDMA/133
> 
> We got our "link is slow to respond" and "device not ready" back for ata1/ata2,
> and enabling the drives after wakeup seems to be reliable.
> 
> Unfortunately, I don't know much about (S)ATA, so I have no idea what is
> actually going on here. In any case, I'd prefer my kernel not to lose my drives
> on a regular basis, so I'll gladly take any pointers on what the best way to fix
> this is :)
> 
> Best regards,
> Matthias

-- 
Damien Le Moal
Western Digital Research