Re: ahci: sata hotplug doesn't work after suspend

[Lin Ming <ming.m.lin@intel.com>]

On Mon, 2012-02-20 at 13:52 +0100, Jiri Slaby wrote:
> On 02/20/2012 09:30 AM, Lin Ming wrote:
> > On Sun, 2012-02-19 at 22:17 +0100, Holger Macht wrote:
> >> On So 19. Feb - 21:11:33, Jiri Slaby wrote:
> >>> Hi,
> >>>
> >>> ahci hotplug stopped working here. It always worked (-next-20111206 is
> >>> the last known working for sure). I'm using -next and after plugging a
> >>> sata disk in, nothing happens. I don't *think* (in the traffic, it's
> >>> hard to tell for sure) an interrupt is generated either. I also *think*
> >>> that it works before suspend/resume, but not after. (Or maybe uptime
> >>> matters?)
> >>>
> >>> This happens before suspend on plug-in:
> >>> ata3: exception Emask 0x50 SAct 0x0 SErr 0x40d0800 action 0xe frozen
> >>> ata3: irq_stat 0x00000040, connection status changed
> >>> ata3: SError: { HostInt PHYRdyChg CommWake 10B8B DevExch }
> >>> ata3: hard resetting link
> >>> ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
> >>> ata3.00: ATA-8: ST31000528AS, CC38, max UDMA/133
> >>> ata3.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32)
> >>> ata3.00: configured for UDMA/133
> >>> ata3: EH complete
> >>> scsi 2:0:0:0: Direct-Access     ATA      ST31000528AS     CC38 PQ: 0 ANSI: 5
> >>> sd 2:0:0:0: [sdc] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB)
> >>> sd 2:0:0:0: [sdc] Write Protect is off
> >>> sd 2:0:0:0: [sdc] Mode Sense: 00 3a 00 00
> >>> sd 2:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't
> >>> support DPO or FUA
> >>>  sdc: sdc1 sdc2
> >>> sd 2:0:0:0: [sdc] Attached SCSI disk
> >>>
> >>> After suspend/resume and plug-in, nothing appears in dmesg. Storing "- -
> >>> -" to /sys/class/scsi_host/host*/scan doesn't help. It looks like the
> >>> line is completely dead, because only ata1 and ata2 say "hard resetting
> >>> link" after this (and another two disks are connected there).
> >>>
> >>> I tried 'echo adapter >host_reset', but I get 'write error: Invalid
> >>> argument'.
> >>>
> >>> 00:1f.2 SATA controller [0106]: Intel Corporation 82801IR/IO/IH
> >>> (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] [8086:2922] (rev 02)
> >>> (prog-if 01 [AHCI 1.0])
> >>>         Subsystem: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port
> >>> SATA Controller [AHCI mode] [8086:2922]
> >>>         Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
> >>> ParErr- Stepping- SERR- FastB2B- DisINTx+
> >>>         Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
> >>> <TAbort- <MAbort- >SERR- <PERR- INTx-
> >>>         Latency: 0
> >>>         Interrupt: pin B routed to IRQ 43
> >>>         Region 0: I/O ports at cc00 [size=8]
> >>>         Region 1: I/O ports at c880 [size=4]
> >>>         Region 2: I/O ports at c800 [size=8]
> >>>         Region 3: I/O ports at c480 [size=4]
> >>>         Region 4: I/O ports at c400 [size=32]
> >>>         Region 5: Memory at feb7c800 (32-bit, non-prefetchable) [size=2K]
> >>>         Capabilities: [80] MSI: Enable+ Count=1/16 Maskable- 64bit-
> >>>                 Address: fee0100c  Data: 4171
> >>>         Capabilities: [70] Power Management version 3
> >>>                 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> >>> PME(D0-,D1-,D2-,D3hot+,D3cold-)
> >>>                 Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> >>>         Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
> >>>         Capabilities: [b0] Vendor Specific Information: Len=06 <?>
> >>>         Kernel driver in use: ahci
> >>>
> >>> Any ideas what that could be?
> >>
> >> I suspect this is caused by commit
> >> 9ee4f3933930abf5cc34f8e9d69fe0e08c18f602. Maybe you could verify? I
> >> bisected this a couple of days ago but didn't have time to look into it
> >> further. Maybe Lin can help here if this is the problematic commit.
> > 
> > I'll try to re-produce this issue first.
> 
> Ok, just a few more information. Suspend/resume cycle is needed to see
> the issue. Reverting of 9ee4f3933930 helps when this is applied too (I
> haven't tried one or the other alone):

I saw the issue after suspend/resume.
Hotplug doesn't work because the port is runtime suspended.

I'll fix it.

Thanks,
Lin Ming

> 
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5305,25 +5305,16 @@ static int ata_port_suspend_common(struct device
> *dev, pm_message_t mesg)
> 
>  static int ata_port_suspend(struct device *dev)
>  {
> -       if (pm_runtime_suspended(dev))
> -               return 0;
> -
>         return ata_port_suspend_common(dev, PMSG_SUSPEND);
>  }
> 
>  static int ata_port_do_freeze(struct device *dev)
>  {
> -       if (pm_runtime_suspended(dev))
> -               pm_runtime_resume(dev);
> -
>         return ata_port_suspend_common(dev, PMSG_FREEZE);
>  }
> 
>  static int ata_port_poweroff(struct device *dev)
>  {
> -       if (pm_runtime_suspended(dev))
> -               return 0;
> -
>         return ata_port_suspend_common(dev, PMSG_HIBERNATE);
>  }
> 
> @@ -5339,16 +5330,7 @@ static int ata_port_resume_common(struct device *dev)
> 
>  static int ata_port_resume(struct device *dev)
>  {
> -       int rc;
> -
> -       rc = ata_port_resume_common(dev);
> -       if (!rc) {
> -               pm_runtime_disable(dev);
> -               pm_runtime_set_active(dev);
> -               pm_runtime_enable(dev);
> -       }
> -
> -       return rc;
> +       return ata_port_resume_common(dev);
>  }
> 
>  static const struct dev_pm_ops ata_port_pm_ops = {
> 
> 
>